Effect of pre-treatment with fine particle peening on surface properties and wear resistance of gas blow induction heating nitrided titanium alloy
Effect of pre-treatment with fine particle peening on surface properties and wear resistance of gas blow induction heating nitrided titanium alloy
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DOI：
10.1016/j.surfcoat.2018.11.088
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发表时间：
2019-02
影响因子：
5.4
通讯作者：
Shogo Takesue;S. Kikuchi;H. Akebono;Y. Misaka;J. Komotori
中科院分区：
文献类型：
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作者：
Shogo Takesue;S. Kikuchi;H. Akebono;Y. Misaka;J. Komotori
为了开发钛合金低温快速渗氮工艺，在气吹感应加热渗氮之前进行了细颗粒强化（FPP）。采用x射线衍射、光学显微镜、扫描电镜、激光显微镜和显微维氏硬度测试对FPP和GBIH渗氮处理后的Ti-6Al-4V合金的表面组织进行了表征。结果表明：FPP预处理加速了氮在GBIH渗氮过程中向钛中的扩散，在相对较低的温度（923 K）下，Ti-6Al-4V合金表面形成了一层氮化层，没有发生晶粒粗化和相变，也没有只经过GBIH渗氮形成一层氮化层。这是因为FPP预处理产生了细粒表面层。对制备的试样进行了往复球盘磨损试验，考察了试样的耐磨性。经FPP预处理后的Ti-6Al-4V合金经GBIH低温渗氮处理后，由于表面形成了坚硬的氮化合物层，其耐磨性得到了提高。结果表明，所提出的表面处理工艺能够在低温、短时间内有效地改善钛合金的表面性能，同时避免晶粒粗化和相变。
In order to develop a rapid nitriding process for titanium alloy at a low temperature, fine particle peening (FPP) was performed prior to gas blow induction heating (GBIH) nitriding. The surface microstructures of a Ti-6Al-4V alloy treated by FPP and GBIH nitriding were characterized using X-ray diffraction, optical microscopy, scanning electron microscopy, laser microscopy and micro-Vickers hardness testing. The results indicate that nitrogen diffusion into titanium during GBIH nitriding was accelerated by the pre-treatment with FPP, and a nitrided layer was formed on the surface of the Ti-6Al-4V alloy at a relatively low temperature (923 K), which grain coarsening and phase transformation did not occur and a nitrided layer was not formed only by GBIH nitriding. This is because a fine-grained surface layer was generated by the pre-treatment with FPP. Reciprocating ball-on-disk wear tests were carried out to examine the wear resistance of the prepared specimens. GBIH nitriding at a low temperature improved the wear resistance of the Ti-6Al-4V alloy following the pre-treatment with FPP, due to the formation of a hard nitrogen compound layer at the surface. The results show that the proposed surface treatment process was effective at modifying the surface properties of a titanium alloy at a low temperature and within a short span of time while avoiding grain coarsening and phase transformation.