List of top Metallurgical Engineering Questions on Metallurgy asked in GATE MT

A dislocation loop PQRSTU is on the (111) plane of a cubic single crystal with Burgers vector \( \vec{b} = \frac{a}{6}[\bar{1}\bar{2}1] \). The dislocation segments \(\vec{PU}\) and \(\vec{PQ}\) are parallel to \([0\bar{1}1]\) and \([1\bar{1}0]\) directions, respectively. The correct statement(s) is/are

A specimen containing maximum initial surface crack of size 1.5 mm is subjected to cyclic loading with \( \sigma_{max} = 300 \) MPa and \( \sigma_{min} = 0 \) MPa. Assuming specimen geometric factor of 1, and referring to the given figure, the crack growth rate in \(\mu\)m cycle\(^{-1}\) is ................... (round off to nearest integer). 

The alloy A (given in the phase diagram) is cooled slowly from the liquid state to just below the eutectic temperature. The ratio of weight fractions of pro-eutectic \(\alpha\) to eutectic \(\alpha\) is ................... (round off to 1 decimal place). 

 

For the given schematic TTT diagram of an eutectoid steel, the following statement(s) is/are true for the heat treatment schedules HT-1, HT-2, and HT-3. 

The mechanism of creep for a single crystal as depicted in the schematic is 

 

An elutriator is used to separate particles based on their sizes in flowing air as shown in the figure. Assuming spherical particles, the diameter (\(D_{50}\)) of the suspended particles which have 50% chance to report to overflow by turbulent air flow is expressed as 

For the equation \( \begin{vmatrix} x+3 & 3x+4 & 4x+5 \\ -2 & -3 & -4 \\ -3 & -4 & -5 \end{vmatrix} = 0 \) the value of \( x \) is ................... (in integer).
Copper ore assaying 10 wt.% Cu is fed to a concentration plant at the rate of 100 tons/h. If the grades of concentrate and tailing are 30 wt.% Cu and 1 wt.% Cu, respectively, the percentage recovery of copper in concentrate is ................... (round off to nearest integer).
Given: 1 ton = 1000 kg
Diffraction pattern of a polycrystalline BCC metal is obtained using monochromatic X-rays of wavelength 0.25 nm. If the first peak occurs at Bragg angle (\(\theta\)) of 30\(^{\circ}\), then the radius of the metal atom in nm is ................... (round off to 2 decimal places).
In an aqueous solution of Fe\(^{2+}\) ions with concentration of 10\(^{-4}\) M at 298 K and atmospheric pressure, the reduction potential of Fe in volt is ................... (round off to 2 decimal places).
Given: Standard reduction potential, \(E^{\circ}_{\text{Fe}^{2+}/\text{Fe}} = -0.44\) V
Faraday's constant, F = 96500 C per mole of electrons
Universal gas constant, R = 8.314 J mol\(^{-1}\)K\(^{-1}\)
Strain hardening behavior of an alloy is given by \( \sigma = 1100 \epsilon^{0.3} \), where \( \sigma \) and \( \epsilon \) are true stress and true strain, respectively. The alloy is cold drawn to an unknown amount of strain, followed by tensile testing. If the tensile test showed 10% reduction in area at maximum load, then the unknown amount of strain from prior cold work is ................... (round off to 2 decimal places).
Identify the INCORRECT statement(s)
Compared to top gating, the effect(s) of bottom gating in sand mold casting is/are
Which of the following is/are the role(s) of coke in a blast furnace?
Match the processes in Column I with the corresponding applications in Column II.
Column I
(P) Fused salt electrolysis
(Q) Carbothermal reduction
(R) Oxidation-refining
(S) Matte converting
Column II
(1) Ironmaking
(2) Aluminium extraction
(3) Copper extraction
(4) Steelmaking
Match the welding techniques in Column I with the most appropriate applications in Column II.
Column I
(P) Submerged arc welding
(Q) Electroslag welding
(R) Shielded metal arc welding
(S) Resistance spot welding
Column II
(1) Thick sections
(2) Surfacing and repair
(3) Thin sheets
(4) Flat position
Match the transport processes in Column I with the relationships in Column II.
Column I
(P) Molecular momentum transport
(Q) Molecular mass transport
(R) Molecular energy transport
(S) Radiation energy transport
Column II
(1) Stefan-Boltzmann law
(2) Newton's law of viscosity
(3) Fick's law
(4) Fourier law
For supersonic O\(_2\) jet in basic oxygen furnace steelmaking, choose the correct combination from the following:
(1) Converging-diverging nozzle
(2) Diverging-converging nozzle
(3) O\(_2\) velocity greater than sound velocity at nozzle throat (Mach number > 1)
(4) O\(_2\) velocity equal to sound velocity at nozzle throat (Mach number = 1)
(5) Exit O\(_2\) jet pressure \(\ge\) atmospheric pressure
(6) Exit O\(_2\) jet pressure \(<\) atmospheric pressure
The non-destructive testing technique(s) for detecting internal defects in a steel component is/are
The condition(s) for high degree of mutual substitutional solid solubility for two metals is/are
A liquid of density 900 kg m\(^{-3}\) is flowing over a flat plate with a free stream velocity of 0.1 m s\(^{-1}\). The laminar boundary layer thickness at a distance of 0.2 m from the leading edge of the plate is 0.007 m. The viscosity of the liquid in centipoise is ................... (round off to 2 decimal places).
Given: 1 centipoise = 10\(^{-3}\) kg m\(^{-1}\)s\(^{-1}\)
The rate constant of a reaction at 400 K is three times the value at 300 K. The activation energy of the reaction in kJ mol\(^{-1}\) is ................... (round off to 1 decimal place).
Given: Universal gas constant, R = 8.314 J mol\(^{-1}\)K\(^{-1}\)
Which of the following is/are responsible for reducing the high cycle fatigue life of a component?
Among the following options, a process for liquid-liquid separation is
The most effective concentration step for sulfide ores is