An investment of $76,000 in equipment that will reduce the time for machining self-locking fasteners will save $29,000 per year. At an interest rate of 8% per year, Estimate the number of years required to recover the initial investment. Round up your answer to the higher whole number.

If the thermal strain developed in polyimide film during deposition is given as 0.0044. assume room temperature is kept at 17.3 c, and thermal coefficient of expansion for the film and the substrate are 54 x 10^-6c^-1 and 3.3 x 10^-6c^-1respectively. calculate the deposition temperature.

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.

What is the heat treatment of metals? what is the benefit of it? why and how it's useful? answer in details, do not write by hand.