Effect of annealing treatment in the mechanical proprty of chromium carbides films

Abstract

Applications of thin film technology have grown quickly, including thermal insulation, cutting tools, solar cells, protection against oxidation and corrosion, and microelectronics. The use of thermoelectric thin films, which have several advantages over bulky sensors (such as sensors of: heat flow, radiation, pressure, electric power, and thermocouples), is widespread. Chromium carbides are widely attracted for industrial applications by their good hardness, high chemical stability, and toughness. The presence of carbon in the composition of chromium metal improves the hardness and the wear resistance by lubricating effect. In this work, the chromium carbides films deposited from pure Cr target by the PVD method on steel substrates are developed and characterized. In this study, the samples are annealed under vacuum in a temperature range between 800 and 1000 °C. The improvement of the mechanical property of thin Cr films is due in particular to the fact that the hardness and wear obtained in this temperature range are very important. The increase in hardness is attributed to the formation of hard binary Chromium carbides. However, its decrease was related with the diffusion of iron and the transformation of binary chromium carbides to ternary carbides at higher annealing temperatures.