The following yield strength, grain diameter, and heat treatment time (for grain growth) data were gathered for an iron specimen that was heat-treated at 750°c. using these data, compute the yield strength of a specimen that was heated at 750°c for 1 h. assume a value of 2 for n, the grain diameter exponent. heat treating time (hr) grain diameter (mm) yield strength (mpa) 7.5 2.5x10-2 3402 1.4x10-2 390

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented

Aturning operation is performed with following conditions: rake angle of 12°, a feed of 0.35 mm/rev, and a depth of cut of 1.1 mm. the work piece is aluminum alloy 6061 with t6 heat treatment (a16061-t6). the resultant chip thickness was measured to be 1.0 mm. estimate the cutting force, fc. use shear stress of 207 mpa and coefficient of friction on the tool face of 0.6.

For each of the following process: a) sketch the p-v diagram, b)sketch t-s diagram, c) sketch t-v diagram, d) sketch the boundary work on one of the diagrams (a, b or c) and e) sketch the reversible heat transfer on one of the diagrams (a, b or c): 1- isobaric process from compressed liquid to superheated vapor 2- isothermal process from compressed liquid to superheated vapor 3- isentropic process from compressed liquid to superheated vapor