The Relationship between Lubrication and Surface Condition of Metals Deformed under Compression : 2nd Report, Experimental Study

Abstract

In the first report, it was found through analysis that the surface condition of a compressed specimen depends on the film thickness of liquid lubricant and the roughening rate of free surface during deformation when the initial surface is flat. In this report, an experimental study on film thickness and roughening rate of free surface is presented. The film thickness on a round aluminium specimen compressed at low speed is proportional to D^2/3V^1/3p^1/3 where D is diameter of the specimen, ν is viscosity of the lubricant and p is the loading rate. The roughening rate of free surface increases with an increasing grain size of the specimen material. From an additional experiment, it is found that the true contact area with tool increases with grain size, and experimental result agrees qualitatively well with the analysis.