What is the orientation of the cutting edge in orthogonal machining?
The cutting edge is perpendicular to the direction of cutting velocity.
p.31
Casting Processes and Terms
What are the advantages of shell casting?
Dimensional accuracy, smoother surface finish, ability to cast very thin sections, and requires a small amount of sand.
p.18
Non-Traditional Machining Methods
What is the primary mechanism of Water Jet Machining?
A narrow jet of water is directed at high pressure and velocity.
p.5
Velocity Diagram in Metal Cutting
What does the velocity triangle help determine in metal cutting?
The relationship between cutting speeds and angles.
p.2
Geometry of Cutting Tools
What does Fig. 1.7 illustrate?
Different types of views of cutting tools.
p.36
Welding Techniques and Types
What type of welding machines are good for manual welding?
Constant current welding machines.
What is the formula for average roughness (Ra) in an ideal surface?
Ra = (4 * tan(cot(s) * e * h * f * C) + C) / 4.
p.31
Casting Processes and Terms
What is investment casting?
A process where ceramics are formed around wax patterns to create a casing for molten metal.
p.17
Non-Traditional Machining Methods
What force is applied to the tool in Ultrasonic Machining?
A downward feed force, F.
p.44
Welding Techniques and Types
What distinguishes upset welding from other welding techniques?
It produces coalescence over the entire area of abutting surfaces by heat obtained from resistance to electric current.
p.4
Shear Angle and Chip Thickness Ratio
What is cutting shear strain (ϵ)?
The magnitude of strain that develops along the shear plane due to machining action.
p.43
Welding Techniques and Types
Where is the maximum heat generated in resistance welding?
At the interface between the two plates being joined.
p.7
Force and Power in Metal Cutting
What does the Merchant Circle Diagram (MCD) represent?
It illustrates the force relations in orthogonal cutting.
p.12
Types of Chips in Machining
What does ECM stand for in machining?
Electro Chemical Machining.
p.31
Casting Processes and Terms
What is shell casting?
A process where sand mixed with thermosetting resin is allowed to contact a heated metal pattern to form a shell.
p.26
Casting Processes and Terms
What is the definition of gating ratio?
Gating ratio is defined as the ratio of sprue area to runner area to ingate area.
p.31
Casting Processes and Terms
What are the limitations of shell casting?
Expensive patterns, small size castings only, cannot obtain highly complicated shapes, and requires sophisticated equipment.
p.26
Casting Processes and Terms
Why is the sprue tapered?
The sprue is tapered to gradually reduce the cross section and eliminate the problem of air aspiration.
p.2
Geometry of Cutting Tools
What is the geometry of a single point turning tool?
It refers to the shape and angles of the cutting tool used in turning operations.
p.20
Casting Processes and Terms
What is the casting process?
A process in which molten metal flows by gravity or other force into a mold where it solidifies in the shape of the mold cavity.
p.45
Welding Techniques and Types
What is the main feature of Laser Beam Welding (LBW)?
It utilizes heat from a high-power concentrated laser beam to melt metal interfaces.
p.20
Casting Processes and Terms
What is sand casting?
A specific type of casting process that uses sand as the mold material.
p.4
Shear Angle and Chip Thickness Ratio
What is the chip thickness ratio (r) formula?
r = ct / c0 = sin(φ) / cos(φ - α).
p.2
Geometry of Cutting Tools
What does Fig. 1.6 represent?
A single point cutting tool.
p.18
Non-Traditional Machining Methods
What is Water Jet Machining (WJM)?
A non-traditional machining method that uses a narrow jet of water directed at high pressure and velocity against the surface of a workpiece.
p.5
Shear Angle and Chip Thickness Ratio
What is the typical value of the shear zone thickness in turning?
1/10th or 10% of the shear plane length.
p.19
Non-Traditional Machining Methods
What does the variable 'D' represent in the MRR equation for AJM?
Mean diameter of abrasives.
How does the width of the cutting edge compare to the workpiece width in orthogonal machining?
The cutting edge is wider than the workpiece width and extends beyond the workpiece on either side.
p.26
Casting Processes and Terms
What are the two types of sprue designs mentioned?
Straight sprue and tapered sprue.
p.44
Welding Techniques and Types
What is percussion welding?
A welding technique similar to flash welding that uses a rapid discharge of stored electrical energy to create an intense arc for a very short duration.
p.27
Casting Processes and Terms
When should risers solidify in relation to the casting?
Risers must solidify after the casting.
p.16
Force and Power in Metal Cutting
What does E s represent in the context of EDM?
Spark energy, calculated as E s = (1/2) × C × V c^2 / cycle.
p.34
Welding Techniques and Types
What is Electric Arc Welding?
A welding process where an arc is generated between cathode and anode to establish the flow of current.
p.8
Force and Power in Metal Cutting
What is the relationship between cutting speed (v) and diameter (D) in turning?
v = π * D * N, where N is the spindle speed.
p.13
Non-Traditional Machining Methods
What does the ECM formula relate to?
It relates the weight of a material to current and time.
p.23
Casting Processes and Terms
When is a Split Pattern or Two-Piece Pattern used?
For intricate castings where withdrawal from the mould is difficult.
p.9
Tool Wear and Tool Life
What causes tool wear during machining?
Sliding of the tool along the machined surface and temperature rise.
p.34
Welding Techniques and Types
What is straight polarity in Electric Arc Welding?
When DC is used and the work is positive (the anode of the circuit).
p.12
Types of Chips in Machining
What is the primary method discussed in section 2.1 of the GATE WALLAH Mechanical Handbook?
Electro Chemical Machining (ECM).
p.44
Welding Techniques and Types
What is projection welding?
A welding process that uses heat generated by electric current to join metal pieces, capable of welding thicker materials than spot welding.
p.44
Welding Techniques and Types
How does flash welding differ from upset welding?
Flash welding uses arc heating instead of resistance heating.
p.34
Welding Techniques and Types
What is welding?
A process by which two materials, usually metals, are permanently joined together by coalescence induced by temperature, pressure, and metallurgical conditions.
p.24
Casting Processes and Terms
What type of sand should core sand be compared to moulding sand?
Core sand should be of higher strength than moulding sand.
p.28
Casting Processes and Terms
What condition must be met for the riser to solidify last according to Caine's Method?
x must be greater than 1.
p.9
Tool Wear and Tool Life
What are the variables in Taylor's Tool Life Equation?
V (cutting speed), T (time), n (exponent), C (constant).
p.38
Welding Techniques and Types
What is the purpose of the coating on arc welding electrodes?
To prevent contamination of the electrode.
p.41
Welding Techniques and Types
What does OFW stand for in welding?
Oxy-fuel welding (fusion welding).
p.32
Casting Processes and Terms
What is a key advantage of True Centrifugal Casting?
Mechanical properties of centrifugally cast jobs are better compared to other processes.
p.46
Welding Techniques and Types
What is Friction Welding (FRW)?
A solid-state welding process that generates heat through mechanical friction between workpieces in relative motion.
What is the formula for peak to valley roughness (h) in an ideal surface?
h = tan(cot(s) * e * f * C) + C.
p.5
Shear Angle and Chip Thickness Ratio
What is the significance of the un-deformed chip thickness in turning?
It helps in understanding the cutting process and tool engagement.
p.32
Casting Processes and Terms
What is a characteristic of Hot Chamber Die Casting?
The die casting alloy is melted in a furnace located within the equipment.
p.33
Casting Processes and Terms
What materials are used in Plaster Casting?
A slurry of plaster, water, and various additives.
In orthogonal machining, how many directions do the cutting forces act?
The cutting forces act along two directions only.
p.33
Casting Processes and Terms
What is Loam Moulding?
A process using artificially composed loam made of brick-clay and sharp sand, restricted to forms that cannot be cast conveniently in other processes.
p.43
Welding Techniques and Types
What distinguishes resistance seam welding from spot resistance welding?
Resistance seam welding uses wheel-shaped electrodes and the workpiece rolls between them.
p.23
Casting Processes and Terms
What is the purpose of a Gated Pattern?
To integrate the gating and runner system with the pattern, improving productivity by eliminating hand cutting.
p.27
Casting Processes and Terms
What is the formula for total solidification time according to Chvorinov's rule?
Total solidification time (t_s) = n * (V_B / A), where n = 1.5 to 2.0.
p.34
Welding Techniques and Types
Where is the majority of heat generated in Electric Arc Welding?
65% to 75% heat is generated at the anode.
p.8
Force and Power in Metal Cutting
How is specific cutting pressure (P_c) calculated?
P_c = F_c / A, where F_c is the cutting force and A is the cross-section area of the undeformed chip.
p.28
Casting Processes and Terms
What are 'a', 'b', and 'c' in Caine's Method?
Constants used in the equation for calculating x.
p.23
Casting Processes and Terms
What does a Cope and Drag Pattern consist of?
Two halves of the pattern along with gating and riser systems, attached to plates with alignment pins.
p.15
Non-Traditional Machining Methods
What type of electrical process is ECG?
A low-voltage high-current electrical process.
p.27
Casting Processes and Terms
How is modulus defined in the context of casting?
Modulus = Volume / Surface area.
p.5
Shear Angle and Chip Thickness Ratio
What is the shear strain rate in metal cutting?
ε̇ = V_s / t_s, where t_s is the thickness of the shear zone.
p.19
Non-Traditional Machining Methods
What is the relationship between Material Removal Rate (MRR) and flow rate of abrasives in AJM?
MRR is proportional to QD, where Q is the flow rate of abrasives and D is the mean diameter of abrasives.
p.45
Welding Techniques and Types
What is the typical depth to width ratio for joints produced by Laser Beam Welding?
Ranging between 4 and 10.
p.18
Non-Traditional Machining Methods
What factors can affect the Material Removal Rate (MRR) in Water Jet Machining?
Different parameters such as pressure, velocity, and nozzle design.
p.14
Non-Traditional Machining Methods
How is MRR calculated for an alloy in ECM?
MRR = (3 eq EI cm^3)/(F sec) where eq = (100 F ρ)/(Σ i xi 100 x v and E A)
p.10
Economics of Metal Cutting
What does T_c represent in the context of metal cutting economics?
Tool changing time (in minutes).
p.9
Tool Wear and Tool Life
What is the wear rate in the primary wear zone?
The wear rate is constant.
p.40
Welding Techniques and Types
What are the major characteristics of submerged arc welding?
High welding speeds and high deposition rates.
p.9
Tool Wear and Tool Life
How does wear change in the tertiary wear zone?
Wear gradually increases.
p.23
Casting Processes and Terms
What is a Single Piece Pattern?
An inexpensive and the simplest type of pattern.
p.27
Casting Processes and Terms
What does Chvorinov's rule state about riser shape?
A good riser shape has a long freezing time, meaning a small surface area per unit volume.
p.44
Welding Techniques and Types
What is the principle behind electro slag welding?
It generates heat by an electric current passing between a consumable electrode and the workpiece through molten slag.
p.32
Casting Processes and Terms
What is the process of True Centrifugal Casting?
Molten metal is introduced into a rotating mold and held against the mold wall by centrifugal force until solidified.
p.10
Economics of Metal Cutting
What components make up the machining cost (C_m)?
Labour cost and overhead cost per minute.
p.9
Tool Wear and Tool Life
What is the extended or modified Taylor's equation used for?
To account for depth of cut and feed rate in tool life calculations.
p.23
Casting Processes and Terms
What is a Match Plate Pattern?
A pattern where cope and drag patterns, along with gating and riser ring, are mounted on a single matching plate.
p.39
Welding Techniques and Types
What is the purpose of using an inert gas in welding?
To drive away other atmospheric gases from the weld zone.
p.7
Force and Power in Metal Cutting
What is the relationship for the actual cutting force R in orthogonal cutting?
R = F_c * t * F * sin(α) + F * cos(α).
p.25
Casting Processes and Terms
What does the ASTM grain size number indicate?
Low numbers mean a few massive grains; high numbers refer to many small grains.
p.7
Force and Power in Metal Cutting
What is the formula for the friction angle φ according to Merchant Analysis?
φ = (4/2) * π * (α + β) - (b).
p.38
Welding Techniques and Types
What are the disadvantages of arc blow?
1. Low heat penetration 2. Excessive weld spatter.
p.46
Welding Techniques and Types
What is a key characteristic of Explosion Welding?
It is done at room temperature and can occur in air, water, or vacuum.
p.25
Casting Processes and Terms
What does 't top' represent in the top gate design?
Filling time in the top gate.
p.45
Welding Techniques and Types
What is Electron Beam Welding (EBW)?
A process where a beam of electrons is magnetically focused on the work piece in a vacuum chamber.
p.26
Casting Processes and Terms
What is the purpose of a sprue in casting?
The sprue is the channel through which molten metal is brought into the parting plane to enter the runners and gates, ultimately reaching the mould cavity.
p.13
Non-Traditional Machining Methods
What is the principle behind Electrochemical Machining (ECM)?
It is the reverse of electroplating.
p.14
Non-Traditional Machining Methods
What is the formula for Material Removal Rate (MRR) for pure metal in ECM?
MRR = (3 AI cm^3)/(vF sec) = (3 EI cm^3)/(F sec)
p.36
Welding Techniques and Types
What is the definition of OCV?
The maximum rated voltage between open terminals under no loading conditions.
p.33
Casting Processes and Terms
What is Squeeze Casting?
A process where molten metal is poured into an open face die, and a punch applies pressure while the part solidifies.
p.14
Non-Traditional Machining Methods
What does the equation I = (V - ∆V) / R represent in ECM?
It represents the current (I) in terms of applied voltage (V), over voltage (∆V), and resistance (R).
p.4
Velocity Diagram in Metal Cutting
Why are velocities needed in the cutting zone?
To obtain power estimates.
p.8
Force and Power in Metal Cutting
What does A_c represent in the context of Metal Removal Rate?
A_c is the cross-section area of the uncut chip (mm²).
p.13
Non-Traditional Machining Methods
Which non-traditional machining method has the highest metal removal rate?
Electrochemical Machining (ECM).
p.33
Casting Processes and Terms
What is the advantage of a Hot Blast Cupola?
It preheats the air blast using flue gases, resulting in higher temperatures than conventional cupolas.
p.29
Casting Processes and Terms
What are external chills used for in casting?
To accelerate the cooling of various regions and promote directional solidification.
p.27
Casting Processes and Terms
What is the relationship between the solidification times of different shapes?
T_sp : T_cy : T_cu = 1 : 0.763 : 0.649.
p.30
Casting Processes and Terms
How can shrinkage cavities be compensated for in casting?
By proper feeding of liquid metal and placing risers in the mold.
p.22
Casting Processes and Terms
What are the main types of pattern allowances?
Shrinkage, draft, machining, distortion, and rapping allowances.
p.29
Casting Processes and Terms
What are internal chills and their purpose?
Pieces of metal placed within the mold cavity to absorb heat and promote rapid solidification.
p.22
Casting Processes and Terms
What is liquid shrinkage?
The reduction in volume when metal changes from liquid to solid state.
p.38
Welding Techniques and Types
What are the drawbacks of a long arc in welding?
1. Large heat loss into atmosphere 2. Unstable arc 3. Weld pool is not protected 4. Weld has low strength, less ductility, poor fusion, and excessive spatter.
p.6
Geometry of Cutting Tools
Is turning considered orthogonal cutting?
No, turning is not orthogonal cutting (2-D).
p.23
Casting Processes and Terms
What is a Follow Board Pattern used for?
For castings with structurally weak portions that need support during ramming.
p.21
Casting Processes and Terms
What is a pattern in casting?
A replica of the final object to be made, with some modifications.
p.41
Welding Techniques and Types
What is the purpose of a high-pressure oxygen jet in gas cutting?
To burn the metal and blow it away, causing the cut (kerf).
p.5
Velocity Diagram in Metal Cutting
What is the formula for the velocity triangle in metal cutting?
sin(2v) = sin(2s) * (v/cos(φ - α))
p.36
Welding Techniques and Types
What type of welding machines are suitable for automatic welding?
Constant voltage machines.
p.16
Tool Wear and Tool Life
What is the formula for wear ratio in Electro Discharge Machining (EDM)?
Wear ratio = Volume of metal removed from work / Volume of metal removed from tool.
p.13
Non-Traditional Machining Methods
In ECM, what role does the work-piece play?
The work-piece is made the anode.
p.16
Velocity Diagram in Metal Cutting
What is the charging current formula in the EDM process?
i c = (1 / R) × V 0 × e^(-t/τ).
p.15
Non-Traditional Machining Methods
How is the heat generated in the gap during fluid flow analysis calculated?
H = I² × R, where I is the current and R is the resistance of the electrolyte in the gap.
p.10
Economics of Metal Cutting
What is the significance of C_t in metal cutting?
Tooling cost (in Rs. per servicing or replacement).
p.28
Casting Processes and Terms
What does Caine's Method relate to in casting?
The freezing ratio, which is the ratio of cooling characteristics of casting to the riser.
p.37
Welding Techniques and Types
What characteristic should manual arc welding equipment have?
Drooping characteristics to maintain constant current when arc length changes.
p.22
Casting Processes and Terms
What are chills used for in casting?
To increase the cooling rate of castings.
p.16
Velocity Diagram in Metal Cutting
What parameters are involved in the relaxation circuit for generating pulses in EDM?
Open circuit voltage (V 0), charging resistance (R), and capacitance (C).
p.46
Welding Techniques and Types
What is the order of Heat Affected Zone (HAZ) from least to most for different welding processes?
Laser beam welding < MIG welding < Submerged arc welding < Arc welding.
p.37
Welding Techniques and Types
What does the duty cycle in welding equipment specify?
The number of minutes within a 10-minute period a welder can safely produce a particular welding current.
p.41
Welding Techniques and Types
Is pressure involved in Oxy-fuel welding?
No, pressure is not involved.
p.38
Welding Techniques and Types
Why must the arc length in welding be kept short?
1. Heat is concentrated 2. More stable 3. More protective atmosphere.
p.24
Casting Processes and Terms
What does the permeability of a core refer to?
The ability of gases to escape through the core.
p.22
Casting Processes and Terms
What is solid shrinkage?
The reduction in volume when a metal loses temperature in the solid state.
p.40
Welding Techniques and Types
When is an oxidizing flame used?
When welding some nonferrous alloys such as copper-base alloys and zinc base alloys.
p.12
Types of Chips in Machining
What is the significance of Electro Chemical Machining?
It is a non-traditional machining method.
p.20
Casting Processes and Terms
What happens to molten metal in the casting process?
It solidifies in the shape of the mold cavity.
p.26
Casting Processes and Terms
What does the equation h_t = H signify in bottom gate design?
It indicates that the height of the top gate equals the height of the bottom gate.
p.17
Non-Traditional Machining Methods
What is the purpose of the tool's vibration in Ultrasonic Machining?
To facilitate the machining process.
What is the relationship between the chip velocity and the cutting edge in orthogonal cutting?
The chip generated flows on the rake face of the tool with chip velocity perpendicular to the cutting edge.
p.13
Non-Traditional Machining Methods
What factors influence the Material Removal Rate (MRR) in ECM?
The atomic weight of the work material.
p.32
Casting Processes and Terms
What type of alloys is Hot Chamber Die Casting suitable for?
Low melting point alloys.
p.15
Non-Traditional Machining Methods
What is the formula for heat absorbed by the electrolyte?
H_e = q ρ_e c_e (T_f - T_i), where q is the flow rate, ρ_e is the density, c_e is the specific heat, T_i is the initial temperature, and T_f is the final temperature.
p.10
Economics of Metal Cutting
What does C_m represent in the economics of metal cutting?
Machining cost (in Rs. per minute).
p.9
Tool Wear and Tool Life
What does Taylor's Tool Life Equation relate to?
It relates cutting speed, time, and tool life.
p.29
Casting Processes and Terms
How is the shape factor (SF) defined?
SF = Length + Width + Thickness.
p.22
Casting Processes and Terms
What is a riser in casting?
A reservoir of molten metal that allows hot metal to flow back into the mould cavity during solidification.
p.24
Casting Processes and Terms
What are some binders used in core sand?
Linseed oil, core oil, resins, dextrin, molasses.
p.42
Welding Techniques and Types
What is powder cutting used for?
To cut metals that are difficult to cut by oxy-fuel cutting, such as cast iron and stainless steel.
p.21
Casting Processes and Terms
What materials are commonly used to make a cover in casting?
Mostly cast iron, although wood is also used sometimes.
p.40
Welding Techniques and Types
What temperature can be produced in oxyacetylene welding?
About 3300° C in the oxidizing flame.
p.33
Casting Processes and Terms
What is a Crucible Furnace typically used for?
It is preferred by smaller foundries for melting metal.
p.8
Tool Wear and Tool Life
What is 'flank wear' associated with?
Flank wear occurs at low speed and is referred to as 'slow death.'
p.40
Welding Techniques and Types
What is an oxidizing flame?
A flame produced with a higher oxygen/acetylene ratio (O2 > C2H2), hotter than the neutral flame.
p.33
Casting Processes and Terms
What methods are used in Casting Cleaning (Fettling)?
Strainer, Bottom well, and Skim bob.
p.29
Casting Processes and Terms
What are gas defects in sand castings?
Defects caused by the trapping of gas in molten metal or mold gases during pouring.
p.30
Casting Processes and Terms
What leads to metal penetration in casting?
Molten metal entering gaps between sand grains, resulting in a rough surface.
p.21
Casting Processes and Terms
What is the parting line in casting?
The dividing line between the two moulding flasks that makes up the sand mould.
p.6
Force and Power in Metal Cutting
What are the two orthogonal components of the resultant force in metal cutting?
Fc (horizontal) and Ft (vertical).
p.21
Casting Processes and Terms
What is moulding sand?
Freshly prepared refractory material used for making the mould cavity, typically a mix of 90% sand, 3% water, and 7% clay.
p.3
Shear Angle and Chip Thickness Ratio
What is the chip thickness ratio (r) formula?
r = sin(φ) / (cos(φ) * V t / V l).
p.35
Welding Techniques and Types
What is the electrode polarity for negative and positive in welding?
Negative: 70% heat at work end; Positive: 30% heat at work end.
p.43
Welding Techniques and Types
What is the overall resistance like in spot resistance welding?
Very low between the overlapping plates.
p.31
Casting Processes and Terms
What are the advantages of investment casting?
Exceptional surface polish, high dimensional precision, ability to cast complicated elements, and compatibility with almost any metal.
p.13
Non-Traditional Machining Methods
What is passed between the anode and cathode in ECM?
A high-amperage direct current through an electrolyte.
p.27
Casting Processes and Terms
What is the purpose of risers in casting?
To feed liquid metal to the solidifying casting and compensate for solidification shrinkage.
p.36
Welding Techniques and Types
What is the definition of SCC?
The maximum rated current required during arc generation.
p.14
Non-Traditional Machining Methods
What is the relationship between current density (J) and current (I) in ECM?
J = I / A, where A is the cross-sectional area of the electrode.
p.44
Welding Techniques and Types
What is thermit welding?
A welding process that uses heat from an exothermic reaction between metal oxides and reducing agents to produce coalescence between metals.
p.32
Casting Processes and Terms
Which alloys are commonly used in Cold Chamber Die Casting?
Aluminum, Copper, Brass, Magnesium, etc.
p.28
Casting Processes and Terms
In Caine's Method, what does 'Y' represent?
The ratio of the volume of the riser to the volume of the casting.
p.10
Economics of Metal Cutting
What factors contribute to tooling cost (C_t)?
Tool regrind cost and tool depreciation per service/replacement.
p.15
Non-Traditional Machining Methods
What happens to the surface metal during ECG?
It is changed to a metal oxide, which is then ground away by the abrasives.
p.38
Welding Techniques and Types
What are the components of the coating material in an arc welding electrode?
1. Deoxidizing agent 2. Arc stabilizing agent 3. Slag forming agent.
p.6
Shear Angle and Chip Thickness Ratio
What is the formula for uncut chip thickness in metal cutting?
t0 = fsin(λ), where f is feed and λ is approach angle.
p.34
Welding Techniques and Types
What is reverse polarity in Electric Arc Welding?
When the work is negative and the electrode is positive.
p.42
Welding Techniques and Types
What is plasma cutting?
A process that uses an ionized gas jet to cut materials resistant to oxy-fuel cutting.
p.21
Casting Processes and Terms
What is the cope in casting?
The upper moulding flask.
p.38
Welding Techniques and Types
What is arc blow in DC arc welding?
A phenomenon that occurs during the welding of magnetic materials with DC, particularly noticeable with bare electrodes.
p.6
Shear Angle and Chip Thickness Ratio
What is the relationship between depth of cut and width of chip in orthogonal cutting?
w = d/sin(λ), where w is width of chip and d is depth of cut.
p.7
Force and Power in Metal Cutting
What is the significance of the angle β in the Merchant Circle Diagram?
It represents the friction angle.
p.38
Welding Techniques and Types
When is arc blow more common?
In DC welding with bare electrodes.
p.21
Casting Processes and Terms
What is backing sand?
Made up of used and burnt sand.
p.21
Casting Processes and Terms
What is a sprue in casting?
The passage through which molten metal from the pouring basin reaches the mould cavity.
p.35
Welding Techniques and Types
What is the oxide cleaning action in AC welding?
Yes, it occurs once every half cycle.
p.10
Economics of Metal Cutting
What is the formula for optimum tool life for minimum cost in metal cutting?
T_o = 1/T_c * (C_n / (C_m + C_t))
p.9
Tool Wear and Tool Life
What are the three zones of flank wear in metal cutting?
Primary wear zone, Secondary wear zone, Tertiary wear zone.
p.32
Casting Processes and Terms
What is the production capacity of Hot Chamber Die Casting compared to Cold Chamber Die Casting?
Hot Chamber Die Casting has a higher production capacity due to shorter casting cycles.
p.22
Casting Processes and Terms
What is the purpose of a chaplet in casting?
To support cores inside the mould cavity.
p.34
Welding Techniques and Types
What are the main factors that induce coalescence in welding?
Temperature, pressure, and metallurgical conditions.
p.32
Casting Processes and Terms
What is a disadvantage of Cold Chamber Die Casting?
It has longer casting cycles, resulting in less product capacity.
p.15
Non-Traditional Machining Methods
What does the equation l²R = q ρ_e c_e (T_f - T_i) represent?
It accounts for all the heat losses in the system.
p.10
Economics of Metal Cutting
What is the formula for optimum tool life for maximum productivity?
T_o = 1/T_c * (n / (n - 1))
p.15
Non-Traditional Machining Methods
What is the tool electrode in Electrochemical Grinding (ECG)?
A rotating, metal bonded, diamond grit grinding wheel.
p.37
Welding Techniques and Types
What is the formula for heat input in welding?
Heat input = b Vl A v (Joule/mm³)
p.22
Casting Processes and Terms
What is a pattern in the casting process?
A replica of the object to be made, with modifications.
p.24
Casting Processes and Terms
What is the general composition of a core sand mixture?
Core oil (1%) and water (2.5 to 6%).
p.8
Tool Wear and Tool Life
What are the types of tool wear mentioned?
Flank wear, crater wear, and chipping off of the cutting edge.
p.21
Casting Processes and Terms
What is the drag in casting?
The lower moulding flask.
p.40
Welding Techniques and Types
What is a neutral flame in oxyacetylene welding?
A flame produced with an oxygen/acetylene ratio of about 1:1, which is chemically neutral.
p.15
Non-Traditional Machining Methods
What role do abrasive particles play in ECG?
They act as an insulating spacer.
p.23
Casting Processes and Terms
What is the function of a Loose Piece Pattern?
Used when the contour of the part makes it difficult to withdraw the pattern from the mould.
p.39
Welding Techniques and Types
Which gases are commonly used in gas shielded welding?
Argon, helium, nitrogen, carbon dioxide, and mixtures of these gases.
p.37
Welding Techniques and Types
What are the functions of electrode coating in welding?
Provide a protective atmosphere, stabilize the arc, provide protective slag, reduce spatter, add alloying elements, and affect arc penetration.
p.6
Types of Chips in Machining
What are the three types of chips in machining?
Continuous chip, Discontinuous chip, Continuous chip with Built-Up Edge (BUE).
p.42
Welding Techniques and Types
What is spot welding?
A type of resistance welding that joins metals by applying pressure and passing current.
p.39
Welding Techniques and Types
What applications are suitable for Submerged Arc Welding (SAW)?
Pressure vessels, ship bridges, LPG cylinders, etc.
p.21
Casting Processes and Terms
What is a runner in casting?
The passageways in the parting plane through which molten metal flow is regulated before reaching the mould cavity.
p.31
Casting Processes and Terms
What are the limitations of investment casting?
Costly patterns and molds, high labor costs, and limited size.
p.24
Casting Processes and Terms
What is the purpose of a core in casting?
To make cavities and hollow projections.
p.8
Force and Power in Metal Cutting
What is the formula for Metal Removal Rate (MRR) in orthogonal cutting?
MRR = A_c * v = w * t_0 * v.
p.13
Non-Traditional Machining Methods
What is the typical voltage and current combination used in commercial ECM?
Low voltage and high current.
p.33
Casting Processes and Terms
What is the primary use of a Cupola furnace?
It is the most widely used furnace for melting cast iron.
p.30
Casting Processes and Terms
What causes shrinkage cavities in casting?
Liquid shrinkage occurring during the solidification of the casting.
p.14
Non-Traditional Machining Methods
What is the significance of specific resistance of electrolyte (S) in ECM?
It affects the current flow and efficiency of the machining process.
p.46
Welding Techniques and Types
What are the shielding methods used in welding?
Flux coating, Flux granules, CO2, Vacuum.
p.32
Casting Processes and Terms
What is the difference between True Centrifugal Casting and Semi-Centrifugal Casting?
Semi-Centrifugal Casting uses centrifugal force to assist the flow of metal from a central reservoir to the extremities of a rotating mold.
p.33
Casting Processes and Terms
What is the chief advantage of an Induction Furnace?
The heat source is isolated from the charge, allowing slag and flux to get heat directly from the charge.
p.30
Casting Processes and Terms
What is a scab defect in casting?
Occurs when a portion of the mold face lifts or breaks down, filled by metal.
p.7
Force and Power in Metal Cutting
What does the equation N = F_c * t * F * cos(α) - F * sin(α) represent?
The normal force in the Merchant Circle Diagram.
p.21
Casting Processes and Terms
What is a pouring basin?
A small funnel-shaped cavity at the top of the mould into which molten metal is poured.
p.35
Welding Techniques and Types
What is the effect of straight polarity (electrode negative) in d.c. welding?
It results in a lower deposition rate.
p.14
Non-Traditional Machining Methods
What does the variable 'A' represent in the context of ECM?
A represents the atomic weight.
p.42
Welding Techniques and Types
Why is cutting cast iron difficult?
Its melting temperature is lower than iron oxide.
p.21
Casting Processes and Terms
What is a flask in casting?
A box-like structure made of rectangular or circular walls, without a bottom or top.
p.29
Casting Processes and Terms
What materials are external chills made from?
High-heat-capacity, high-thermal-conductivity materials.
p.27
Casting Processes and Terms
What is the modulus method in riser design?
If the modulus of the riser exceeds the modulus of the casting by a factor of 1.2, feeding during solidification is satisfactory.
p.24
Casting Processes and Terms
What is the formula for net buoyancy force in casting?
Net Buoyancy Force = Weight of Liquid Metal Displaced – Weight of Core.
p.41
Welding Techniques and Types
How can flux be used in welding?
As a powder, in a flux paste, or pre-coated on rods.
p.30
Casting Processes and Terms
What causes the cut and washes defect?
Insufficient strength of molding sand and high velocity of molten metal flow.
p.24
Casting Processes and Terms
Why do cores need to have higher permeability?
To allow gases evolving from molten metal to escape.
p.39
Welding Techniques and Types
What is the main characteristic of Tungsten Inert Gas (TIG) welding?
An arc is established between a non-consumable tungsten electrode and the workpiece.
p.42
Welding Techniques and Types
What is a key advantage of resistance welding?
No other materials are needed to create the bond, making it cost-effective.
p.23
Casting Processes and Terms
What is a Skeleton Pattern?
A pattern made of strips of wood used to build the final pattern by packing sand around it.
p.3
Geometry of Cutting Tools
What does the Orthogonal Rake System (ORS) include?
Inclination angle (i), orthogonal rake angle (α), side relief angle (γ), end relief angle (γ1), end cutting edge angle (C e), principal cutting edge angle (λ), and nose radius (R).
p.46
Welding Techniques and Types
What important factors are considered in Explosion Welding?
Critical velocity and critical angle.
p.30
Casting Processes and Terms
What is mold shift in casting defects?
Occurs when cope and drag or molding boxes are not properly aligned.
p.42
Welding Techniques and Types
How is powder cutting performed?
By injecting finely divided 200-mesh iron powder into the flame.
p.30
Casting Processes and Terms
What are cut and washes in molding material defects?
Rough spots and areas of excess metal caused by erosion of molding sand by flowing metal.
p.8
Tool Wear and Tool Life
What is 'crater wear' associated with?
Crater wear occurs at high speed and is also referred to as 'slow death.'
p.21
Casting Processes and Terms
What is a cheek in casting?
An intermediate moulding flask used in three-piece moulding.
p.42
Welding Techniques and Types
What is resistance welding?
The joining of metals by applying pressure and passing current through the metal area to be joined.
p.23
Casting Processes and Terms
What is a Sweep Pattern used for?
To generate large shapes that are axi-symmetrical or prismatic, such as bell-shaped or cylindrical.
p.30
Casting Processes and Terms
What is fusion in casting defects?
Fusion of sand grains with molten metal, giving a brittle, glassy appearance.
p.21
Casting Processes and Terms
What is a bottom board in casting?
A board, normally made of wood, used at the start of the mould making.
p.30
Casting Processes and Terms
What are inclusions in casting?
Particles of slag, refractory materials, or deoxidation products trapped in the casting.
p.35
Welding Techniques and Types
What are the three modes of metal transfer in welding?
Globular, spray, and short-circuit.
p.10
Economics of Metal Cutting
What does V represent in the context of metal cutting?
Cutting speed (in m/min).
p.46
Welding Techniques and Types
What is the role of the 'upset' in Friction Welding?
It is a lateral force that plastically displaces and fuses the materials.
p.32
Casting Processes and Terms
What is Slush Casting?
A variation of the permanent mold process where metal remains in the mold until a shell of desired thickness forms, then the remaining liquid is poured out.
p.9
Tool Wear and Tool Life
In the modified Taylor's equation, what do 'd' and 'f' represent?
'd' represents depth of cut and 'f' represents feed rate.
p.8
Tool Wear and Tool Life
What does 'chipping off of the cutting edge' signify?
It signifies 'sudden death' of the tool.
p.25
Casting Processes and Terms
Why is the velocity in the top gate important?
Because it minimizes the time taken to fill the mold and the temperature gradient.
p.39
Welding Techniques and Types
How is the arc generated in Gas Metal Arc Welding (GMAW)?
Between a consumable electrode and the workpiece.
p.46
Welding Techniques and Types
Which metals are well suited for Explosion Welding?
Metals prone to brittle joints when heat welded, such as aluminum on steel and titanium on steel.
p.21
Casting Processes and Terms
What is a core in casting?
Used for making hollow cavities in castings.
p.3
Shear Angle and Chip Thickness Ratio
What does the term 'chip compression ratio' refer to?
It is another name for the inverse of chip ratio (h), where h > 1.
p.35
Welding Techniques and Types
What is a bead in welding?
The metal added during a single pass of welding, made of the same material as the base metal.
p.29
Casting Processes and Terms
Why must internal chills be made from the same alloy as the casting?
Because they become part of the final casting.
p.46
Welding Techniques and Types
What is Ultrasonic Welding (USW)?
A solid-state welding process that uses high-frequency vibrations to join materials under light pressure.
p.22
Casting Processes and Terms
What materials are commonly used for patterns?
Wood, metal, and wax (for investment casting).
p.29
Casting Processes and Terms
What are the two classifications of gas defects?
Blowholes and pinhole porosity.
p.3
Geometry of Cutting Tools
What is the rule to remember tool designation in ANSI or ASA?
Rake (α b α s), relief (γ e γ s), cutting edge (C e C s), side comes last, finish with nose radius (inch).
p.30
Casting Processes and Terms
What causes swell in casting dimensions?
Movement of the mold wall under met allostatic forces.
p.25
Casting Processes and Terms
What is the formula for calculating filling time in the bottom gate?
t bottom = 2(1)(2) t t g A h h H A g - -.
p.35
Welding Techniques and Types
What is the heat balance in the arc for AC welding?
50% at work end and 50% at electrode end.
p.22
Casting Processes and Terms
Why are metal patterns more advantageous than wood patterns?
They are more dimensionally stable and durable.
p.39
Welding Techniques and Types
What is a key feature of Submerged Arc Welding (SAW)?
The arc is submerged under solid flux, preventing heat transfer loss and splashing.
p.30
Casting Processes and Terms
What is a mis-run defect in casting?
When metal is unable to fill the mold cavity completely, leaving unfilled cavities.
p.35
Welding Techniques and Types
What is RPDC arc-welding preferred for?
Difficult tasks such as overhead welding.
p.3
Geometry of Cutting Tools
What is the relationship between inclination angle (i) and cutting types?
For orthogonal cutting, i = 0; for oblique cutting, i ≠ 0.
p.3
Shear Angle and Chip Thickness Ratio
What is the relationship between shear angle (φ) and chip thickness ratio (r)?
tan(φ) = (cos(α) / sin(α)) * (1 - r) / r.
p.30
Casting Processes and Terms
What causes a cold shut in casting?
When two streams of metal do not fuse together properly in the mold cavity.
p.21
Casting Processes and Terms
What is a gate in casting?
The actual entry point through which molten metal enters the mould cavity at a controlled rate.
