TiC含量对激光选区熔化Inconel 625合金微观组织及表面摩擦磨损性能的影响

为了提高3D打印镍基高温合金强度、硬度及耐磨性能,使用激光选区熔化技术(Selective laser melting,SLM)制备添加不同质量分数TiC增强Inconel 625合金材料,并对比添加不同质量分数TiC(4 wt.%和8 wt.%)所制备的SLM TiC/Inconel 625试样的摩擦磨损性能。结合X射线衍射仪(XRD),金相显微镜(OM),扫描电子显微镜(SEM)及能谱分析(EDS)等材料表征手段对TiC/Inconel 625试样的物相分布,微观组织结构及磨损前后的元素分布进行对比分析。结果表明,随着TiC含量的增高,SLM TiC/Inconel 625硬度从325 HV_(0.2)(不含TiC)升高到了587 HV_(0.2)(SLM 8 wt.%TiC/Inconel 625),磨损率也由22.4×10~(-5)mm~3/(N·m)下降为9.8×10~(-5)mm~3/(N·m)。其中,平均摩擦磨损系数最小的为SLM 4 wt.%Ti C/Inconel 625 (COF=0.47)。综合对比可以发现通过添加适量的TiC颗粒可以有限改善SLM Inconel 625的硬度及耐磨损性能。

Effect of TiC on Microstructure and Wear Properties of Inconel 625 Alloy Fabricated via Selective Laser Melting Technology

In order to improve the strength, hardness and wear resistance of nickel-based superalloys, selective laser melting ( SLM) technology is used to fabricate Inconel 625 alloy with different TiC content. The friction and wear properties of SLM TiC/ Inconel 625 samples with a series of TiC content (4 wt. % and 8 wt. %) are in-depth studied and analyzed. The phase distribution, microstructure and element distribution before and after wear tests of the SLM TiC/ Inconel 625 samples are investigated using X-ray diffractometer (XRD), metallographic microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and other advanced material characterization methods. The results show that with the increase of TiC content, the hardness of SLM TiC/ Inconel 625 increased from 325 HV_{0. 2}(without TiC) to 587 HV_{0. 2}(with 8 wt. % TiC). The wear rate of these samples was also decreased from 22. 4×10^-5 mm³ / (N·m) to 9. 8×10^-5 mm³ / (N·m). Among these samples, SLM TiC/ Inconel specimen (with 4 wt. %) has the lowest average coefficient of friction (COF= 0. 47). It is proved that the hardness and wear resistance of SLM Inconel 625 samples canbe enhanced by adding an appropriate amount of TiC particles.