Structural and micromechanical properties of ion-beam mixed tungsten-on-steel system

Structural and micromechanical properties of ion-beam mixed tungsten layers were studied. 45 nm thick W layers deposited on HSS substrates were Kr-ion-beam mixed at temperatures ranging from RT up to 450°C. The samples mixed at RT are amorphous. Increase of the process temperature results in the formation of crystalline layers. Amorphous layer are characterized by low friction coefficient and relatively low hardness. Crystallization of layers results in the increase of their hardness and friction coefficient. Wear rates of ion-beam mixed layers are always lower when compared with untreated steel substrates. The results are discussed in the frames of the model assuming the presence of thin, soft layer on hard substrate.