Question

In the case of un-reactive contacting surfaces, the fatty acids adheres by chemical reaction during lubrication.

(a) True

(b) False

I have been asked this question during an online interview.

Question is taken from Friction and Lubrication in Metal Forming topic in section Types of Die & Metal Forming Processes of Casting-Forming-Welding II

Answer 1

Right option is (b) False

Easiest explanation: In lubrication, the hydrocarbon layers are meant to reduce the friction and wear under loading conditions. In the case of un-reactive contacting surfaces, the fatty acids only adhere by physical adsorption. For the reactive metal surfaces, the mechanism of chemical adsorption is likely to occur, which combines both the physical and chemical adsorption.