Xu Wei, Li Yong, Du Hu, Wang Qiulin, Xu Rutao, Zhao Guoyang
Chengdu Aeronautic Polytechnic, Chengdu, 610100, China.
Chengdu Pump Application Technology Research Institute, Chengdu, 610207, China.
Sci Rep. 2025 Apr 13;15(1):12744. doi: 10.1038/s41598-025-97951-y.
To enhance the surface properties of titanium alloys and meet the design requirements for high efficiency and stability, this study employs hot isostatic pressing (HIP) technology to post-process the hot-dip aluminum coating on titanium alloy surfaces. The research investigates the impact of HIP on the microstructure and performance of the hot-dip aluminum coating. Initially, a hot-dip aluminum coating was prepared on the TA15 titanium alloy surface, and the causes of defects were analyzed. Subsequently, the coating underwent post-processing, involving remelting and repair under high temperature and pressure conditions. Microhardness tests were conducted on the interface area near the coating under various processing conditions, and the morphology, microstructure, and elemental distribution of the coating were analyzed. The mechanism by which HIP eliminates defects in the hot-dip aluminum coating and enhances its performance was also explored. Experimental results indicate that samples without post-processing exhibit a microstructure characterized by through-going cracks, a loose transition layer with poor density and porosity, as well as numerous shrinkage pores and cavities. After HIP treatment at 600 °C, the outer coating and transition layer become more porous, with increased defect formation, primarily in the form of pores and cracks. Some portions of the transition layer and original bonding layer transform into a thicker bonding layer. Following HIP treatment at 800 °C, cracks and pores are significantly reduced, the atomic ratio of Ti to Al in the bonding layer approaches 1.17, forming a more stable intermetallic compound, along with the emergence of a new phase, AlV. Defects such as pores and cavities are repaired, leading to improved surface hardness across all regions of the coating. Consequently, the microstructure and performance of the titanium alloy surface hot-dip aluminum coating are effectively enhanced.
为提高钛合金的表面性能，满足高效稳定的设计要求，本研究采用热等静压（HIP）技术对钛合金表面热浸铝涂层进行后处理。研究了HIP对热浸铝涂层微观结构和性能的影响。首先，在TA15钛合金表面制备热浸铝涂层，并分析缺陷产生的原因。随后，对涂层进行后处理，即在高温高压条件下进行重熔和修复。对不同加工条件下涂层附近的界面区域进行显微硬度测试，并分析涂层的形貌、微观结构和元素分布。还探讨了HIP消除热浸铝涂层缺陷并提高其性能的机理。实验结果表明，未经后处理的样品微观结构存在贯穿裂纹、密度和孔隙率较差的疏松过渡层，以及大量缩孔和空洞。在600℃进行HIP处理后，外层涂层和过渡层孔隙增多，缺陷形成增加，主要表现为孔隙和裂纹。过渡层和原始结合层的部分区域转变为更厚的结合层。在800℃进行HIP处理后，裂纹和孔隙显著减少，结合层中Ti与Al的原子比接近1.17，形成更稳定的金属间化合物，同时出现新相AlV。孔隙和空洞等缺陷得到修复，涂层各区域的表面硬度均有所提高。因此，钛合金表面热浸铝涂层的微观结构和性能得到有效提升。
