Mechanical behaviour of sputtered M-Fe-C (M = Cr, Mo, W) carbides

Transition metal carbides of the VI Group of the Periodic Table (M-C where M = Cr, Mo, W) doped with iron were deposited as thin films on glass substrates by magnetron sputtering and were structurally and mechanically analysed by X-ray diffraction; laser interferometry and ultra-microhardness. The results show that the structures of the M-C binary systems depends on the position of the element M in the Periodic Table. Both W-C and Mo-C systems are crystalline (fcc structure) while the Cr-C is amorphous. The hardness and Young's modulus of the films increase from the carbides of the 1(st) to the 3(rd) long period. The addition of iron decreases the degree of structural order of the films as well as their Young's modulus. The films with higher hardness are those with a transition structure between crystalline and amorphous.