Surface layer modification of AlSi6Cu4 aluminium alloy via CO2 laser treatment

Abstract

The AlSi6Cu4 is a well known aluminium alloy used for internal combustion engine cylinder heads in mass production. Long life of the engine is important requirement in the world-wide automotive market. It is especially appreciated by customers of the product. Engine life is directly connected with the wear resistance problem. The focus of the research carried out was to modify the surface layer of the aluminium alloy using the results of many years of investigations by our research group. This paper summaries the work on surface layer hardening by laser treatment, laser alloying using amorphous boron and laser alloying through cladding a Borotec alloy layer (10009 Eutalloy). The optimum laser treatment parameters, e.g. laser power intensity on irradiated surface, traverse speed and laser beam diameter were selected from a metallographic analysis base, which is also discussed in this paper. The hardness increase obtained in the modified zone of the AlSi6Cu4 aluminium alloy investigated gives a promise of extended internal combustion engine head life. It was improved by having a homogeneous surface layer with much better properties than those obtained by the conventional method.The AlSi6Cu4 is a well known aluminium alloy used for internal combustion engine cylinder heads in mass production. Long life of the engine is important requirement in the world-wide automotive market. It is especially appreciated by customers of the product. Engine life is directly connected with the wear resistance problem. The focus of the research carried out was to modify the surface layer of the aluminium alloy using the results of many years of investigations by our research group. This paper summaries the work on surface layer hardening by laser treatment, laser alloying using amorphous boron and laser alloying through cladding a Borotec alloy layer (10009 Eutalloy). The optimum laser treatment parameters, e.g. laser power intensity on irradiated surface, traverse speed and laser beam diameter were selected from a metallographic analysis base, which is also discussed in this paper. The hardness increase obtained in the modified zone of the AlSi6Cu4 aluminium alloy investigated gives a promise of e...