Modeling nonisothermal laser amorphization: a multicomponent alloy perspective

The processes of melt crystallization and conductive heat transfer during selective laser melting of a metal alloy are considered in a conjugate formulation. A mathematical model is proposed for describing the inhomogeneous temperature field for calculating the fraction of the crystalline phase during laser treatment of the surface of a metal alloy. A numerical study of laser amorphization of bulk metallic glass (BMG) by melting the surface of samples of finite dimensions has been carried out. A comparison with the known experimental data is carried out, and a qualitative agreement is obtained for the calculations on the depth of the melt pool, the homogeneity of the amorphous layer, and its location for a multicomponent alloy based on zirconium: \({Zr}_{57}{Cu}_{\mathrm{15,4}}{Ni}_{\mathrm{12,6}}{Al}_{10}{Nb}_{5}\) ${\mathit{Zr}}_{57}{\mathit{Cu}}_{15,4}{\mathit{Ni}}_{12,6}{\mathit{Al}}_{10}{\mathit{Nb}}_5$ . Potentially suitable laser scanning regimes are identified, in which the fraction of the crystalline phase in the treated layer does not increase compared to the initial one in the initial amorphous-crystalline alloy. It was found that when using the calculated modes of laser scanning, it is possible to reduce the fraction of the crystalline phase in the treated surface layer of the BMG alloy by orders of magnitude.