This paper presents the experimental research and analyses on cracking behavior during high power laser cladding of Stellite alloy and NiCrSiB alloy. The experiments demonstrate that Stellite alloy is not sensitive to cracking. Large area stellite laser clad (length 200 mm, width 56 mm, depth 1.9 mm) was achieved by 18 multi-pass overlap. NiCrSiB alloy is very sensitive to cracking and many transverse macro cracks appear on the clad pass. Most cracks originate from the interface between the clad layer and the substrate and then develop up into the surface, which belongs to the cold crack domain. During multi-pass overlap, the as appeared cracks will develop into previous passes or later passes. The cracking phenomenon and behavior is mainly affected by the dynamic interaction between the stress (strain) induced and the thermal plasticity change of the clad material during the solidification, which is related to physical properties of the cladding material, the microstructure and the solidifaction characteristics of the process. The strength and toughness of the as-cladded layer sometimes is more critical to the crack formation than the residue tensile stress induced during the cladding process.

Date Published: 7 February 2000
PDF: 5 pages
Proc. SPIE 3888, High-Power Lasers in Manufacturing, (7 February 2000); doi: 10.1117/12.377034

Published in SPIE Proceedings Vol. 3888:
High-Power Lasers in Manufacturing
Xiangli Chen; Tomoo Fujioka; Akira Matsunawa, Editor(s)