Mechanical and surface analysis of Ti0.4Al0.6N/Mo multilayers

The quest for hard materials that are able to sustain elevated stresses as tools or cutting processes has led to the investigation of(Ti,Al)N/Mo multi layer coatings. These structures have been deposited by dc magnetron sputte ring on high-speed steel and stainless-steel substrates and designed with m odulation periods of approximately 13 nm, up to a total thickness of 2.8 mu m. Experimental X-ray diffraction (XRD) achieved the basics involving struc tural quality and texture while RES provided the composition. From AFM obse rvations the waviness of the surface was monitored and it was found that th e rms roughness values were minimised for a bias voltage of - 120 V. Ultram icrohardness values of 33 GPa were obtained for the best samples, and their adhesion to the steel substrates was also studied. Residual stress measure ments revealed a compressive stress state that prevailed in these structure s, ranging from - 0.2 to - 1.3 GPa, (C) 2001 Elsevier Science Ltd. All righ ts reserved.