Fabrication of steel-Inconel functionally graded materials by laser melting deposition integrating with laser synchronous preheating
Fabrication of steel-Inconel functionally graded materials by laser melting deposition integrating with laser synchronous preheating
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DOI：
10.1016/j.optlastec.2020.106451
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发表时间：
2020-11
影响因子：
5
通讯作者：
W. Meng;Wenhao Zhang;Wang Zhang;X. Yin;B. Cui
中科院分区：
文献类型：
--
作者：
W. Meng;Wenhao Zhang;Wang Zhang;X. Yin;B. Cui
本文研究了一种功能梯度材料，通过光纤激光熔化沉积和激光同步预热，从316L递增梯度Inconel 625制造。裂纹行为，显微组织演变和显微硬度的梯度材料内的位置的变化进行了测定。未预热样品中的裂纹发生在90%316L/10%Inconel625至70%316L/30%Inconel625的沉积层处，预热样品中没有产生裂纹。实验确定富Nb和Mo相的析出是开裂的主要原因。随着Inconel 625添加量的增加，试样的组织由胞状枝晶转变为明显的柱状枝晶，析出相由（γ + Laves）共晶相转变为（γ + NbC）相。显微硬度沿梯度方向呈近似沿着线性分布。研究表明，激光同步预热可以改善功能梯度材料的显微组织和内应力，从而有助于抑制材料的开裂。
This paper examines a functionally graded material, fabricated by fiber laser melting deposition and laser synchronous preheating that incrementally grades from 316L to Inconel625. The cracking behaviour, microstructure evolution and microhardness were determined as the variation of position within the graded materials. The cracks in the non-preheated samples occurred at the deposited layers from 90% 316L/10% Inconel625 to 70% 316L/30% Inconel625, and no cracks were produced in the preheated samples. Precipitation of Nb- and Mo-enrich phases was experimentally identified to be the main cause of cracking. The microstructure of the preheated samples changed from the cellular dendrites to prominent columnar dendrites, and the precipitated phases were transformed from (γ + Laves) eutectic phase to (γ + NbC) phase with the increase of Inconel625. Microhardness presented an approximate linear distribution along the gradient direction. Work shows that microstructure and internal stress can be improved by laser synchronous preheating, thereby contributing to suppress cracking for the functionally graded material.