Microstructure and texture characteristics of laser-clad Ti6Al4V/NiCr-Cr3C2 composite coating

Abstract

• The recrystallization grains of β-Ti are coarse equiaxed after laser cladding. • GND density of β-Ti near by the Ti 2 C is slightly higher than other places. • Weak textures exist in β-Ti/Ti 2 C/CeO 2 composite coating. • CeO 2 as the heterogeneous nucleation core grows in the same direction with Ti 2 C. • The grains of matrix β-Ti and Ti 2 C had a special orientation relationship. Microstructure and texture characteristics of laser-clad Ti 2 C/CeO 2 /β-Ti composite coatings are investigated. The matrix β-Ti belong to equiaxed recrystallization grains with high-angle grain boundaries (HAGB). The well-developed Ti 2 C dendrites can grow through the multiple β-Ti grains. In addition, the matrix β-Ti grains near Ti 2 C have higher geometrically necessary dislocation (GND) density than that far away from Ti 2 C and within Ti 2 C. Furthermore, the relatively weak texture {1 1 1} 〈1 1 0〉 and {0 0 1} 〈1 0 0〉 exists in matrix β-Ti, and similar rotated cube texture {0 0 1} 〈1 1 0〉 forms in both Ti 2 C and CeO 2 . Besides, the special orientation relationships, 100 β - Ti / / 100 Ti 2 C and 100 β - Ti / / 100 Ti 2 C , are found between Ti 2 C and β-Ti.