Coaxial laser cladding on an inclined substrate

This paper describes an experimental and theoretical study of the cladding mode of coaxial laser cladding on an inclined substrate. Based on the image analysis of the powder stream and clad profile measurements in coaxial las er cladding, it was found that irregular clad profiles always formed on an inclined surface and the location of the peak profile shifted away from the clad center. This phenomenon is caused by uneven distributions of powder c oncentration and laser beam intensity. A modified Gaussian mode for powder stream and laser beam was proposed to estimate the clad profiles on an incl ined plane under laser beam irradiation. The effects of the inclined steel substrate on the CO2 laser beam absorption and stainless-steel powder catch ment were examined experimentally. The results show that both the laser abs orption and the powder catchment on the mild steel decrease with increasing the cladding angle. From the analysis of laser beam mode, the clad width i s equivalent to the beam spot size on the inclined substrate. However, the clad height correlates well with the distribution of the powder concentrati on. The results show that the Gaussian cladding mode could be adopted in va rious laser cladding applications such as rapid prototyping and butt weldin g to predict the clad profiles precisely. (C) 2000 Elsevier Science Ltd. Al l rights reserved.