Solidification of Al6Zn2Mg alloy after laser remelting

Study on the solidification microstructure in AZ91D Mg alloy after laser surface melting

“…This agrees with the solidification theory that relates dendrite cell size and the cooling rate according to the literature [15][16][17][18][19], described by the function l = BÁg Àn , where l is average dendrite cell size in mm, g is the cooling rate in K/s, B is a proportionality constant and n is an exponent ranging from 0.3 to 0.4. This relationship cannot be explained physically, but it can be useful in practice.…”

“…The dendrite cell size or dendrite arm spacing in the lasermelted zone was measured to evaluate the rapid solidification microstructure induced by laser irradiation in the literature [11,14,15,18,19]. In this study, the measurements of dendrite cell size values were the results of the average of 300 calculations carried out in 15 different fields in the specimen.…”

TiC reinforced composite coating produced by powder feeding laser cladding

“…It was worth noting that there was an apparent boundary between the substrate and coating (see Fig. 4(a)), which was due to the planar growth in the bottom of the molten pool [16]. With the increase of distance from the bottom of the coating, the solidification rate rapidly increased and the temperature gradient decreased rapidly, which led the microstructure to change into cellular/dendrite ( Fig.…”

Laser surface processing of ultralight magnesium alloys

“…The effect of cooling rates on the dendrite cell morphology of the laser-melted zone can be understood from It can be seen that as the cooling rate decreases with the melt depth from 10 6 K/s in the top surface to 10 4 K/s in the boundary of the laser-melted zone, the dendrite cell size increases from 0.7  0.1 m to 2.1  0.1 m. This agrees with the solidification theory that relates dendrite cell size and the cooling rate according to the literature (Greenwald et al 1978;Chong et al 2003;Nayak et al 2004;Roόsz et al 1993;, described by the function λ=B γ -n , where λ is average dendrite cell size in m, γ is the cooling rate in K/s, B is a proportionality constant and n is an exponent ranging from 0.3 to 0.4. This relationship cannot be explained physically, but it can be useful in practice.…”

“…The dendrite cell size or dendrite arm spacing in the laser-melted zone was measured to evaluate the rapid solidification microstructure induced by laser irradiation in the literature (Basu et al 2008;Stefanescu and Ruxanda 2004;Chong et al 2003;Nayak et al 2004;Roόsz et al 1993). In this study, the measurements of dendrite cell size values were the results of the average of 300 calculations carried out in 15 different fields in the specimen.…”