Porosity and liquation cracking of dissimilar Nd:YAG laser welding of SUS304 stainless steel to T2 copper

•The mechanism of laser welding defects in stainless steel to copper was investigated.•A model is proposed to illustrate the evolution process of liquation cracking.•Possible solutions were advised to inhibit laser welded defects in dissimilar metals.•It had a good industrial applicability in allowing high quality and efficiency.