# Recent questions and answers in Casting, Forming and Joining Processes A circular hole of $25 \: mm$ diameter and depth of $20 \: mm$ is machined by EDM process. The material removal rate (in $mm^3/min$) is expressed as $4 \times 10^4 \: IT^{-1.23}$ where $I=300 \: A$ and the melting point of the material, $T=1600^{\circ}C$. The time ( in minutes) for machining this hole is _________ (correct to two decimal places)
A welding operation is being performed with voltage $= 30 \: V$ and current =$100 \: A$. The cross-sectional area of the weld bead is $20 \: mm^2$. The work-piece and filler are titanium for which the specific energy of melting is $14 \: J/mm^3$. Assuming a thermal efficiency of the welding process $70 \%$, the welding speed (in $mm/s$) is __________ (correct to two decimal places).
A steel wire is drawn from an initial diameter $(d_i$) of $10 \: mm$ to a final diameter ($d_f$) of the $7.5 \: mm$. The half cone angle ($\alpha$) of the die is $5^{\circ}$ and the coefficient of friction ($\mu$ ... The drawing stress (in MPa) required to carry out this operation is _____ (correct to two decimal places)
Following data correspond to an orthogonal turning of a $100 \: mm$ diameter rod on a lathe. Rake angle:$+15^{\circ}$; Uncut chip thickness: $0.5 mm$; nominal chip thickness after the cut: $1.25 \: mm$ The shear angle (in degrees) for this process is _________ (correct to two decimal places)
Taylor's tool life equation is used to estimate the life of a batch of identical HSS twist drills by drilling through holes at constant feed in $20 \: mm$ thick mild steel plates. In test $1$, a drill lasted $300$ holes at $150$ rpm while in test $2$, ... . The maximum number of holes that can be made by another drill from the above batch at $200$ rpm is_________ (correct to two decimal places).
For sand-casting a steel rectangular plate with dimensions $80 \: mm \times 120 \: mm \times 20 \: mm$, a cylindrical riser has to be designed. The height of the riser is equal to its diameter. The total solidification time for the casting in $2$ minutes. In ... For a solidification time for $3$ minutes in the riser, the diameter (in mm) of the riser is ________ (correct to two decimal places)
Feed rate in slab milling operation is equal to rotation per minute (rpm) product of rpm and number of teeth in the cutter product of rpm, feed per tooth and number of teeth in the cutter product of rpm, feed per tooth and number of teeth in contact
The preferred option for holding an odd-shaped workpiece in a centre lathe is live and dead centres three jaw chuck lathe dog four jaw chuck
Match the following products with the suitable manufacturing process: ... $P-2, Q-1, R-3, S-4$ $P-4, Q-1, R-2, S-3$ $P-1, Q-3, R-4, S-2$
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 $0.865$ $0.826$ $0.777$ $0.632$
A cube and a sphere made of cast iron (each of volume $1000$ $cm^3$) were cast under identical conditions. The time taken for solidifying the cube was $4$ $s$. The solidification time (in $s$) for the sphere is __________
In a two-stage wire drawing operation, the fractional reduction (ratio of change in cross-sectional area to initial cross-sectional area) in the first stage is $0.4$. The fractional reduction in the second stage is $0.3$. The overall fractional reduction is $0.24$ $0.58$ $0.60$ $1.00$
A cube shaped casting solidifies in $5$ $min$. The solidification time in min for a cube of the same material, which is $8$ times heavier than the original casting, will be $10$ $20$ $24$ $40$