On representative stress correlation of global scratch quantities at scratch testing of elastoplastic materials

Scratch testing is studied aiming at correlation of global quantities in the context of a representative stress description. Previous investigations concerning this matter have shown that good accuracy predictions for different material classes, within the framework of classical Mises elastoplasticity, can be achieved by using a combination of stresses at different levels of plastic strains to define representative quantities at scratching. It is important to emphasize though that the correlation must account for the difference in mechanical behavior at elastoplastic and rigid plastic scratching and that pertinent results have only been presented for the normal scratch hardness. It is therefore the aim presently to investigate if such a correlation can be extended to apply also for global scratch quantities in general. From a practical point of view the results are valuable both when describing the mechanical behavior at scratching and at material characterization. Predictions based on the present study can within the framework of classical Mises elastoplasticity and quasi-static conditions, be made for a wide range of materials ranging from polymers and ceramics to metals.