Compare precipitation hardening (Section 11.10) and the hardening of steel by quenching and tempering (Sections 10.5, 10.6, and 10.8) with regard to (a) The total heat treatment procedure (b) The microstructures that develop (c) How the mechanical properties change during the several heat treatment stages

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Abrake has a normal braking torque of 2.8 kip in and heat-dissipating cast-iron surfaces whose mass is 40 lbm. suppose a load is brought to rest in 8.0 s from an initial angular speed of 1600 rev/min using the normal braking torque; estimate the temperature rise of the heat dissipating surfaces.

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?