What is the difference between sintering powders and hot pressing powders? - Answers Hot
pressing includes applying pressure while sintering does not. Sintering is usually done on
ceramic powders while hot pressing is usually done on metal powders.
What happens in a eutectic reaction? - Answers A liquid transforms into 2 solid phases
What happens in a euctectoid reaction? - Answers A solid transforms into 2 other solid phases.
What kind of fracture is associated with the intergranular crack propagation mechanism? -
Answers Brittle fracture. Crack propagation is along grain boundaries.
What is vacancy diffusion? - Answers With vacancy diffusion, atomic motion is from one lattice
site to an adjacent vacancy. Self diffusion and the diffusion of substitutional impurities process
via this mechanism.
What is interstitial diffusion? - Answers When atomic motion is from interstitial site to adjacent
interstitial site.
Polymers are...? - Answers Viscoelastic materials
(T/F) Upon cooling below the melting temperature, the solubility of dissolved elements
undergoes a large increase when metals freeze. - Answers False.
Homogeneous nucleation is favored for (larger/Smaller) supercooling compared with
heterogenous nucleation? - Answers Larger.
Diffusion equation? - Answers D=Do*exp(-Q/(R*T))
(T/F) In an alloy, atoms tend to migrate from regions of high concentration to regions of low
concentration. - Answers True
Theoretical fracture strength? - Answers E/10, where E is the modulus of elasticity.
Maximum stress? - Answers Mean stress + Amplitude stress
Minimum stress? - Answers Mean stress - stress amplitude.
If either stress or temperature is increased... - Answers The steady state creep rate increases
and the rupture lifetime decreases
For most technologically important metal alloys, the usual state or microstructure is - Answers
A metastable one, which is between initial and equilibrium states.
(T/F) Fully recrystallized cold-work metal will possess the same microstructure and properties
of the original material. - Answers False