Advances in Laser Surface Engineering: Tackling the Cracking Problem in Laser-Deposited Ni-Cr-B-Si-C Alloys

作者：Hemmati I^*; Ocelik V; De Hosson J Th M

来源：JOM, 2013, 65(6): 741-748.

DOI：10.1007/s11837-013-0594-3

Laser-deposition technologies are being increasingly used for surface modification and three-dimensional manufacturing applications. The biggest technical obstacle to a wider usage of these technologies especially for deposition of hard alloys is cracking of the deposited samples. In this work, the idea of microstructural refinement as a toughening mechanism for Ni-Cr-B-Si-C alloys deposited by laser cladding is evaluated and a new idea for reducing the cracking tendency of these alloys is proposed. The results show that although a significant refinement of the Cr-rich precipitates in these alloys could be induced by a suitable addition of Nb, the cracking susceptibility of the deposits was unchanged. This was so because the continuous network of hard eutectics was still providing an easy route for crack growth. The outcome of this work shows that an effective toughening mechanism for these alloys should include not only a refinement of the hard precipitates but also modification of the eutectic structure.

• 出版日期2013-6