爆炸喷涂工艺参数对AlCuFeSc准晶涂层力学性能的影响

Effect of Explosive Spraying Process Parameters on Mechanical Properties of AlCuFeSc Quasicrystalline Coatings

目的研究爆炸喷涂工艺参数对AlCuFeSc准晶涂层力学性能的影响规律,进一步提升铝合金表面AlCuFeSc准晶涂层的性能。方法采用爆炸喷涂工艺制备准晶涂层,以正交试验方法对爆炸喷涂氧燃充枪比、喷涂距离、喷涂频率3个影响涂层性能的关键参数进行优化。借助显微硬度计、拉力试验机研究涂层的力学性能。采用SEM、XRD、EDS等手段表征粉末及涂层的微观物相结构。结果在试验参数范围内,以涂层的表面硬度和结合强度性能为主要判定指标,各因素对涂层性能的影响从大到小依次为氧燃充枪比、喷涂距离、喷涂频率。综合考量涂层表面硬度和结合强度2个指标,得到了AlCuFeSc涂层的最佳制备工艺,氧燃充枪比为56%,喷涂距离为210 mm,喷涂频率为1次/s。在该最佳工艺参数下制备的准晶涂层致密且与铝合金基体结合良好,涂层表面硬度为583.4HV0.3,结合强度为63.24 MPa,孔隙率为0.648%,准晶相的含量为69%。结论采用最佳工艺参数制备的AlCuFeSc准晶涂层相较于非最佳工艺参数喷涂涂层,其性能得到较大提高,可为未来准晶涂层的应用提供参考。

Quasicrystals are solid-state ordered phases with both long-range quasi-periodic translational order and non-crystallographic rotational symmetry.They form specific metal alloys and are intermetallic compounds with a narrow composition range.The material exhibits unique rotational symmetry,low density,good thermal insulation performance,low friction coefficient and corrosion resistance,and it has good compatibility with Al/Ti alloy substrates.In recent years,the AlCuFeSc quasicrystalline protective coating has gradually become a popular high-performance protective coating material,which has broad applications and prospects in surface protection in complex environments.However,the currently reported quasicrystalline coating preparation technology is difficult to meet the application requirements of strong bonding and high hardness.Because the crystal state change of the coating during the preparation process is hard to be controlled,resulting in large internal stress and quasicrystalline phase content of the coating.Compared with other spraying methods,explosive spraying has the characteristics of fast particle flight speed,high density,strong bonding strength and uniform structure of the prepared coating.At the same time,it also has the advantage of easy adjustment of flame temperature and spraying rate,and can accurately control the coating.The layer preparation process preserves the quasicrystalline phase components in the powder to the greatest extent and ensures the quality of the coating.In order to study the effect of explosive spraying process parameters on the micro-structures and properties of AlCuFeSc quasicrystalline coatings,and further improve the performance of AlCuFeSc quasicrystalline coatings on aluminum alloy surfaces.In this paper,the quasicrystalline coating was prepared by the explosive spraying process,and three key parameters affecting the properties of the coating,such as the ratio of oxygen-fueled guns,spraying distance and spraying frequency,were optimized by orthogonal tests.The mechanical properties of the coatings were studied with a micro-hardness tester and a tensile testing machine.The microscopic phase structures of the powders and coatings were characterized with a scanning electron microscopy(SEM)and an X-ray diffraction(XRD).The research results showed that within the range of test parameters,the surface hardness and bonding strength of the coating were used as the main judging indicators,and the effect of each factor on the coating performance was in descending order of oxygen-fuel gun ratio,spraying distance,and spraying frequency.Comprehensively considering the two aspects of coating surface hardness and bonding strength,the optimal preparation process of the AlCuFeSc coating was 56%oxygen-fuel filling gun ratio,210 mm spraying distance,and 1 time/s spraying frequency.The quasicrystalline coating prepared under the optimal process parameters was dense and well bonded to the aluminum alloy substrate.The surface hardness of the coating was 583.4HV0.3,the bonding strength was 63.24 MPa,the porosity was 0.648%,and the quasicrystalline phase content was 69%.The AlCuFeSc quasicrystalline coating prepared with the optimal process parameters has an excellent improvement in properties compared with the spray coating with the non-optimal process parameters,which would provide a reference for the application of quasicrystalline coatings in the future.