# Recent questions tagged casting-forming-and-joining-process

A sheet metal with a stock hardness of $250\: HRC$ has to be sheared using a punch and a die having a clearance of $\text{1 mm}$ between them. If the stock hardness of the sheet metal increases to $400\: HRC$, the clearance between the punch and the die should be _________ $mm.$
A strip of thickness $40\:mm$ is to be rolled to a thickness of $20\:mm$ using a two-high mill having rolls of diameter $200\:mm$. Coefficient of friction and arc length in $mm$, respectively are $0.45\:\text{and}\:38.84$ $0.39\:\text{and}\:38.84$ $0.39\:\text{and}\:44.72$ $0.45\:\text{and}\:44.72$
The fluidity of molten metal of cast alloys (without any addition of fluxes) increases with increase in viscosity surface tension freezing range degree of superheat
The cold forming process in which a hardened tool is pressed against a workpiece (when there is relative motion between the tool and the workpiece) to produce a roughened surface with a regular pattern is Roll forming Strip forming Knurling Chamfering
The figure shows a pouring arrangement for casting of a metal block. Frictional losses are negligible. The acceleration due to gravity is $9.81 \: m/s^2$ .The time (in $s$, round off to two decimal places) to fill up the mold cavity (of size $40 \: cm \times 30 \: cm \times 15 \: cm$) is _____
A gas tungsten arc welding operation is performed using a current of $250 \: A$ and an arc voltage of $20 \: V$ at a welding speed of $5 \: mm/s$. Assuming that the arc efficiency is $70 \%$, the net heat input per unit length of the weld will be _________$kJ/mm$ (round off to one decimal place)
The thickness of a sheet is reduced by rolling (without any change in width) using $600 \: mm$ diameter rolls. Neglect elastic deflection of the rolls and assume that the coefficient of friction at the roll-workpiece interface is $0.05$. The sheet enters the ... possible final thickness that can be produced by this process in a single pass is __________ $mm$ (round off to two decimal places).
In a casting process, a vertical channel through which molten metal flows downward from pouring basin to runner for reaching the mold cavity is called blister sprue riser pin hole
Which one of the following welding methods provides the highest heat flux $(W/mm^2)$? Oxy-acetylene gas welding Tungsten inert gas welding Plasma arc welding Laser beam welding
Match the following sand mold casting defects with their respective causes. ... $P-3, Q-4, R-2, S-1$ $P-2, Q-4, R-1, S-3$ $P-3, Q-4, R-1, S-2$
Calculate the punch size in mm, for a circular blanking operation for which details are given below. $\begin{array}{ll} \text{Size of the blank} & 25 \text{ mm} \\ \text{Thickness of the sheet} & 2 \text{ mm} \\ \text{Radical clearance between punch and die} & 0.06 \text{ mm} \\ \text{Die allowance} & 0.05 \text{ mm} \end{array}$ $24.83$ $24.89$ $25.01$ $25.17$
In a DC arc welding operation, the voltage-arc length characteristic was obtained as $V_{arc} = 20+5l$ where the arc length $l$ was varied between $5$ mm and $7$ mm. Here $V_{arc}$ denotes the arc voltage in $Volts$. The arc current was varied from $400$ A and $500$ A. Assuming linear ... current for the welding operation are $45$ V, $450$ A $75$ V, $750$ A $95$ V, $950$ A $150$ V, $1500$ A
In a single pass rolling process using $410$ mm diameter steel rollers, a strip of width $140$ mm and thickness $8$ mm undergoes $10\%$ reduction of thickness. The angle of bite in radians is $0.006$ $0.031$ $0.062$ $0.600$
The homogeneous state of stress for a metal part undergoing plastic deformation is $T = \begin{pmatrix} 10 & 5 & 0 \\ 5 & 20 & 0 \\ 0 & 0 & -10 \end{pmatrix}$ where the stress component values are in MPa. Using von Mises yield criterion, the value of estimated shear yield stress, in MPa is 9.50 16.07 28.52 49.41
A solid cylinder of diameter $100$ mm and height $50$ mm is forged between two frictionless flat dies to a height of $25$ mm. The percentage change in diameter is $0$ $2.07$ $20.7$ $41.4$
An orthogonal cutting operation is being carried out in which uncut thickness is $0.010$ mm, cutting speed is $130$ m/min, rake angle is $15^{\circ}$ and width of cut is $6$ mm. It is observed that the chip thickness is $0.015$ mm, the cutting force is $60$ N and the thrust force is $25$ N. The ratio of friction energy to total energy is _______ (correct to two decimal places).
The maximum reduction in cross-sectional area per pass $(R)$ of a cold wire drawing process is $R=1-e^{-(n+1)}$, where $n$ represents the strain hardening coefficient. For the case of a perfectly plastic material, $R$ is $0.865$ $0.826$ $0.777$ $0.632$
The type of weld represented by the shaded region in the figure is groove spot fillet plug
A strip of $120$ mm width and $8$ mm thickness is rolled between two $300$ mm-diameter rolls to get a strip of $120$ mm width and $7.2$ mm thickness. The speed of the strip at the exit is $30$ m/min. There is no front or back tension. Assuming uniform ... $200$ MPa in the roll bite and $100\%$ mechanical efficiency, the minimum total power (in $kW$) required to drive the two rolls is _______.
It is desired to make a product having $T$-shaped cross-section from a rectangular aluminium block. Which one of the following processes is expected to provide the highest strength of the product? Welding Casting Metal forming Machining
A sprue in a sand mould has a top diameter of $20 \: mm$ and height of $200$ mm. The velocity of the molten metal at the entry of the sprue is $0.5 \: m/s$. Assume acceleration due to gravity as $9.8 \: m/s^{2}$ and neglect all losses. If the mould is well ventilated, the velocity (upto $3$ decimal points accuracy) of the molten metal at the bottom of the sprue is _________ $m/s$
In an arc welding process, welding speed is doubled. Assuming all other process parameters to be constant, the cross-sectional area of the weld bead will Increase by $25\%$ Increase by $50\%$ Reduce by $25\%$ Reduce by $50\%$
Spot welding of two steel sheets each $2 \: mm$ thick is carried out successfully by passing $4 \: kA$ of current for $0.2$ seconds through the electrodes. The resulting weld nugget formed between the sheets is $5 \: mm$ in diameter. Assuming cylindrical shape for the nugget, the thickness of ...
Equal amounts of a liquid metal at the same temperature are poured into three moulds made of steel, copper and aluminum. The shape of the cavity is a cylinder with 15 mm diameter. The size of the moulds are such that the outside temperature of the moulds do not ... , respectively.) Copper - Steel - Aluminum Aluminum - Steel - Copper Copper - Aluminum - Steel Steel - Copper - Aluminum
The Voltage-length characteristics of a direct current arc in an arc welding process is $V=(100+40l)$ ,where $l$ is the length of arc in $mm$ and $V$ is arc voltages in volts.during a welding process,the arc length varies between $1$ and $2 \: mm$ and welding current is in range $200-250 \: A$.Assuming a linear power source,the short circuit current is_____$A$
Gray cast iron blocks of size $100mm\times 50mm\times 10mm$ with a central spherical cavity of diameter $4 \:mm$ are sand cast.The shrinkage allowance for the pattern is $3\%$.The ratio of the volume of the pattern to the volume of casting is
The welding process which uses a blanket of fusible granular flux is tungsten inert gas welding submerged arc welding electroslag welding thermit welding
The part of a gating system which regulates the rate of pouring of molten metal is pouring basin runner choke ingate
Under optimal conditions of the process the temperatures experienced by a copper work piece in fusion welding, brazing and soldering are such that $T_{\text{welding}} > T_{\text{soldering}}> T_{\text{brazing}}$ $T_{\text{soldering}} > T_{\text{welding}} > T_{\text{brazing}}$ ... $T_{\text{welding}} > T_{\text{brazing}} > T_{\text{soldering}}$
A plastic sleeve of outer radius $r_0=1$ $mm$ covers a wire (radius $r=0.5\:mm$) carrying electric current. Thermal conductivity of the plastic is $0.15 W/m-K$. The heat transfer coefficient on the outer surface of the sleeve exposed to air is $25 W/m^2-K$. Due to the addition of the plastic cover, the heat transfer from the wire to the ambient will increase remain the same decrease be zero
Ratio of solidification time of a cylindrical casting (height = radius) to that of a cubic casting of side two times the height of cylindrical casting is ________
In a rolling operation using rolls of diameter $500$ $mm$, if a $25$ $mm$ thick plate cannot be reduced to less than $20$ $mm$ in one pass, the coefficient of friction between the roll and the plate is ________
Which two of the following joining processes are autogeneous? Diffusion welding Electroslag welding Tungsten inert gas welding Friction welding (i) and (iv) (ii) and (iii) (ii) and (iv) (i) and (iii)
In full mould (cavity-less) casting process, the pattern is made of expanded polystyrene wax epoxy plaster of Paris
During a TIG welding process, the arc current and arc voltage were $50$ $A$ and $60$ $V$, respectively, when the welding speed was $150$ $mm/min$. In another process, the TIG welding is carried out at a welding speed of $120$ $mm/min$ at the same arc voltage and heat input ... so that weld quality remains the same. The welding current (in $A$) for this process is $40.00$ $44.72$ $55.90$ $62.25$
The solidification time of a casting is proportional to $\left( \dfrac{V}{A} \right )^2$, where $V$ is the volume of the casting and $A$ is the total casting surface area losing heat. Two cubes of same material and size are cast using sand casting process. The top face of one of the cubes ... face insulated to that of the other cube is $\dfrac{25}{36} \\$ $\dfrac{36}{25} \\$ $1 \\$ $\dfrac{6}{5}$
A DC welding power source has a linear voltage-current ($V$-$I$) characteristic with open circuit voltage of $80$ $V$ and a short circuit current of $300$ $A$. For maximum arc power, the current (in Amperes) should be set as_________
Match the following products with preferred manufacturing processes: ... $P-4, Q-3, R-2, S-1$ $P-2, Q-4, R-3, S-1$ $P-3, Q-4, R-2, S-1$
A cylindrical riser of $6\text{ cm}$ diameter and $6 \text{ cm}$ height has to be designed for a sand casting mould for producing a steel rectangular plate casting of $7 \text{ cm} \times 10 \text{ cm} \times 2 \text{ cm}$ dimensions having the total solidification time of $1.36$ minute. The total solidification time (in minute) of the riser is _______