Adhesion between some tool and work materials in fretting and relation to metal cutting

Adhesion is an important component in the wear of tools and components. Among the methods to quantify adhesion, reciprocating fretting is a possible test method. This paper describes results from reciprocating fretting tests involving cutting tool materials and work materials. Powder metallurgical high speed steel (HSS) tool inserts with and without TiN coating were evaluated for adhesive affinity against a number of aerospace work materials in the form of spherical ended pins in high vacuum. The force required to separate the pin from the flat tool surface obtained from the fretting studies was the parameter used to quantify adhesion. This varied strongly for the different work materials, and TiN coating reduced adhesion appreciably. These results from the fretting studies are discussed in the context of adhesion in metal cutting. While the fretting tests provide a more fundamental information about adhesion, results from milling tests are indicative of the effects of adhesion at stresses and temperature prevalent at tool-chip contact.