Work hardening and the scratch resistance of Ni–Co alloys using a rapid prototyping approach

The propensity of a material to work harden can impart increased resistance to wear. The present study examines a series of Ni–Co alloys that display different hardness and different tendencies for work hardening to better understand the role of work hardening in material removal during scratching. It is found that work hardening has a significant effect on the effective hardness – i.e. the resistance to penetration – during scratching. It is in this determination of the scratch hardness that work hardening plays its most important role in the present material. For a given value of static hardness, the scratch hardness – and hence resistance to scratching - is higher when the work hardening rate is higher. This has important implications for the prediction of scratch resistance using material properties. The work also shows the utility of the concept of scratch ductility in determining material removal during a scratch event and in the use of additive manufacturing techniques to facilitate rapid prototyping in the development of scratch resistant alloys.