To avoid high crack sensitivity of TiB-Ti composite coating during laser cladding process,network-like structure composite coating was fabricated with laser in-situ technique on titanium alloy using 5 μm TiB2 powder ...To avoid high crack sensitivity of TiB-Ti composite coating during laser cladding process,network-like structure composite coating was fabricated with laser in-situ technique on titanium alloy using 5 μm TiB2 powder as the cladding material.The microstructure,phase structure and properties of the coatings were analyzed by SEM,XRD,EPMA,TEM,hardness tester and fretting wear meter.It was observed that the outer ring of the network-like structure was mainly TiB strengthening phase,while the inner ring was α-Ti grain,and the interface between TiB and Ti matrix was very clean and had a consistent orientation relationship.The hardness of the cladding layer with network-like structure gradually decreased from the surface toward the interface,but the average hardness was nearly two times that of the substrate.In the fretting wear test,it was found that the wear resistance of the cladding layer with network-like structure was larger than that of the substrate under low load(40 N).The results revealed that the hardness and fretting wear resistance of the titanium-based composite coating could be improved by the introduction of network-like structure.展开更多
The hollow cylinders of TiB-Ti composites with a gradient distribution of Ti phase were synthesized by the combination of traditional slurry spray with centrifugal forming process.The influences of the concentration o...The hollow cylinders of TiB-Ti composites with a gradient distribution of Ti phase were synthesized by the combination of traditional slurry spray with centrifugal forming process.The influences of the concentration of sodium hexametaphosphate(SHMP),the concentration of polyvinyl alcohol(PVA)and solid content(20 vol%-35 vol%)on the rheological properties of the TiB_(2)-Ti composite slurries were investigated.Slurries with low viscosity,weak thixotropy and shear-thinning behaviour were obtained for facilitating the slurry spraying process.The effects of different centrifugal conditions on the migration of components during the forming process were studied.The phase composition and the elements distribution of the prepared samples were characterized by the energy-dispersive X-ray spectrometer.The observations revealed that the samples fabricated at 1500 r/min for 3 min had a significant composition variation.For two-phase systems with small density differences and large particle size variation,centrifugal time was more important than centrifugal speed in forming a continuous gradient structure.展开更多
利用钛与 B4C,石墨之间的自蔓延高温合成反应经普通的熔铸工艺原位合成制备了等摩尔 Ti C和 Ti B增强的钛基复合材料。光学金相、EPMA、TEM和 X射线衍射的研究结果表明 :存在两种不同形状的增强体 ,即短纤维状 Ti B晶须和等轴、近似等轴...利用钛与 B4C,石墨之间的自蔓延高温合成反应经普通的熔铸工艺原位合成制备了等摩尔 Ti C和 Ti B增强的钛基复合材料。光学金相、EPMA、TEM和 X射线衍射的研究结果表明 :存在两种不同形状的增强体 ,即短纤维状 Ti B晶须和等轴、近似等轴状 Ti C粒子。增强体与 Ti基体界面洁净 ,没有明显的界面反应。由于增强体承受载荷 ,基体合金晶粒细化以及高密度位错的存在 ,制备钛基复合材料的机械性能有了较大的提高。石墨的加入导致形成更多的等轴、近似等轴状 Ti C粒子 ,有利于改善复合材料的性能。展开更多
基金Projects(2019J01813,2018J01557) supported by the Natural Science Foundation of Fujian Province,ChinaProject(2018H0031) supported by the Guiding Science Program of Fujian Province,ChinaProject(2018GP2002) supported by the Science and Technology Program of Putian City,China
文摘To avoid high crack sensitivity of TiB-Ti composite coating during laser cladding process,network-like structure composite coating was fabricated with laser in-situ technique on titanium alloy using 5 μm TiB2 powder as the cladding material.The microstructure,phase structure and properties of the coatings were analyzed by SEM,XRD,EPMA,TEM,hardness tester and fretting wear meter.It was observed that the outer ring of the network-like structure was mainly TiB strengthening phase,while the inner ring was α-Ti grain,and the interface between TiB and Ti matrix was very clean and had a consistent orientation relationship.The hardness of the cladding layer with network-like structure gradually decreased from the surface toward the interface,but the average hardness was nearly two times that of the substrate.In the fretting wear test,it was found that the wear resistance of the cladding layer with network-like structure was larger than that of the substrate under low load(40 N).The results revealed that the hardness and fretting wear resistance of the titanium-based composite coating could be improved by the introduction of network-like structure.
基金National Natural Science Foundation of China(Nos.51521001,51832003,and 51911530153)。
文摘The hollow cylinders of TiB-Ti composites with a gradient distribution of Ti phase were synthesized by the combination of traditional slurry spray with centrifugal forming process.The influences of the concentration of sodium hexametaphosphate(SHMP),the concentration of polyvinyl alcohol(PVA)and solid content(20 vol%-35 vol%)on the rheological properties of the TiB_(2)-Ti composite slurries were investigated.Slurries with low viscosity,weak thixotropy and shear-thinning behaviour were obtained for facilitating the slurry spraying process.The effects of different centrifugal conditions on the migration of components during the forming process were studied.The phase composition and the elements distribution of the prepared samples were characterized by the energy-dispersive X-ray spectrometer.The observations revealed that the samples fabricated at 1500 r/min for 3 min had a significant composition variation.For two-phase systems with small density differences and large particle size variation,centrifugal time was more important than centrifugal speed in forming a continuous gradient structure.
文摘利用钛与 B4C,石墨之间的自蔓延高温合成反应经普通的熔铸工艺原位合成制备了等摩尔 Ti C和 Ti B增强的钛基复合材料。光学金相、EPMA、TEM和 X射线衍射的研究结果表明 :存在两种不同形状的增强体 ,即短纤维状 Ti B晶须和等轴、近似等轴状 Ti C粒子。增强体与 Ti基体界面洁净 ,没有明显的界面反应。由于增强体承受载荷 ,基体合金晶粒细化以及高密度位错的存在 ,制备钛基复合材料的机械性能有了较大的提高。石墨的加入导致形成更多的等轴、近似等轴状 Ti C粒子 ,有利于改善复合材料的性能。
