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试验研究了激光熔覆层的凝固特征和组织形成规律。结果表明:熔覆层不同位置的凝固特征参数不同。熔覆层底部属于典型的平面外延生长组织,且枝晶粗大;而顶部是较规则的树枝状共晶组织;中部为细小的胞晶和柱状晶;且晶体生长受结晶学各向异性影响。熔覆层组织晶粒形核的非均匀形核特征显著。熔覆层微区成分存在着不均匀性,不同元素沿晶间偏析(富集),是组织不均匀的重要原因
Experimental study of the laser cladding layer solidification characteristics and the formation of the law. The results show that the parameters of solidification in different locations of cladding layer are different. The bottom of the cladding layer belongs to the typical plane epitaxial growth structure, and the dendrite is coarse; while the top is the more regular dendritic eutectic structure; the middle is fine cell and columnar crystals; and the crystal growth is affected by the crystallographic anisotropy. Heterogeneous nucleation characteristics of the grain nucleation of the cladding layer are significant. The microstructure of the cladding layer is heterogeneous, segregation (enrichment) of different elements along the intergranular, which is an important reason for the uneven structure