Experimental study on residual stress distribution of laser rapid forming process

The test specimens which consist of Ni20 alloy powder as a cladding metal on the stainless steel 1Crl8Ni9Ti substrate was prepared by using laser rapid forming process and the residual stress distribution in the specimens was analyzed through the hole-drilling method. The results show that the residual stress level in the specimens is lower and belongs to low residual stress domain. The cladding metal near the substrate bore with a compressive stress parallel to the direction of laser scanning. With the increase of the number of cladding layer the value of the compressive stress minimizes gradually and transforms to tensile stress with the value increasing. Conversely, the residual stress perpendicular to the direction of laser scanning is smaller.