Process optimization of Ti–Nb alloy coatings on a Ti–6Al–4V plate using a fiber laser and blended elemental powders
Process optimization of Ti–Nb alloy coatings on a Ti–6Al–4V plate using a fiber laser and blended elemental powders
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DOI：
10.1016/j.jmatprotec.2010.07.030
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发表时间：
2010-11
影响因子：
6.3
通讯作者：
Vahid Fallah;S. Corbin;A. Khajepour
中科院分区：
文献类型：
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作者：
Vahid Fallah;S. Corbin;A. Khajepour
利用光纤激光器，通过沉积Ti-45wt.%Nb的吹塑粉末，对Ti-6Al-4V钢板表面成分进行了改性。采用扫描电子显微镜和能谱仪(EDS)分析了熔覆层的组织结构和化学成分。通过对组合参数、激光比能量、粉末密度和新定义的激光提供能量(即单位质量的能量)的识别，得到了优化的激光加工工艺参数，包括激光功率1100W，激光扫描速度350 mm/min(或∼5.83 mm/S)，激光光斑直径2 mm，送粉速度0.1g/S。结果表明，在这些工艺参数下，可以形成无气孔截面、成分均匀的连续微珠，其成分与β(Ti，Nb)固溶体相一致。此外，在Ti-6Al-4V板表面的Ti-Nb覆层的第二层(即从覆层/基材界面∼1 mm的覆层厚度之后)，Al和V元素被更生物相容性更好的元素Nb彻底取代。
A fiber laser was used to modify the surface composition of a Ti–6Al–4V plate through deposition of the blown powder mixture of Ti–45wt.%Nb. Scanning electron microscopy and energy dispersive spectroscopy (EDS) were employed to examine the clad sections microstructure and chemical composition. The optimized set of laser processing parameters, including the laser power of 1100W, the laser scan speed of 350mm/min (or ∼5.83mm/s), the laser spot diameter of 2mm and the powder feed rate of 0.1g/s was found with the identification of combined parameters, the laser specific energy, the powder density and the newly defined laser supplied energy (i.e. representing the amount of energy given to the unit mass of the blown powder). It is shown that, with these parameters, continuous beads can be formed with pore-free sections and a homogeneous composition corresponding to that of β (Ti, Nb) solid solution phase. Furthermore, Al and V elements are thoroughly replaced with a more biocompatible element, Nb, in the second layer of a Ti–Nb cladding build-up on the surface of the Ti–6Al–4V plate (i.e. after ∼1mm in clad thickness from the clad/substrate interface).