The titanium-based composites were synthesized by powder metallurgy method. The effects of composition and sintering temperature on the microstructure and properties of the titanium-based composites were investigated ...The titanium-based composites were synthesized by powder metallurgy method. The effects of composition and sintering temperature on the microstructure and properties of the titanium-based composites were investigated by X-ray diffraction, optical microscopy, scanning electron microscopy and mechanical properties tests. The results demonstrate that adding ZrO2 particles can improve the mechanical properties of powder metallurgy （P/M） titanium-based composites. The Ti composite with 4% （mole fraction） ZrO2 sintered at 1100 °C for 4 h shows an appropriate mechanical property with a relative density of 93.9%, a compressive strength of 1380 MPa （570 MPa higher than pure Ti） and good plasticity （an ultimate strain above 24%）.展开更多
Reinforcement distribution tailoring has been proven effective in strengthening and toughening titanium matrix composites(TMCs).In this work,the analysis of the Ti64(Ti-6Al-4V)-B phase diagram indicated that B content...Reinforcement distribution tailoring has been proven effective in strengthening and toughening titanium matrix composites(TMCs).In this work,the analysis of the Ti64(Ti-6Al-4V)-B phase diagram indicated that B content dominates the TiB distribution.With this philosophy,B content regulation was applied to tailor homogeneous and network structures in Ti64-B composites fabricated via laser-directed energy deposition additive manufacturing(AM).The unique plate-like TiB attends inhomogeneous composites(Ti64–0.05B).However,in network composite(Ti64–0.25B),the TiB whisker(TiBw)arranges along priorβ-Ti grains with the same orientation.Moreover,the synergistic improvement of strength(988 MPa→1202 MPa),stiffness(106 GPa→116 GPa),hardness(325 HV→362 HV),and uniform elongation(5%→7.8%)were achieved.This work exhibited a balanced strength/ductility trade-off,which provides a good guide on microstructure tailoring.展开更多
为研究SiC_(f)/Ti_(3)Al复合材料在单轴拉伸中产生的热残余应力对拉伸性能的影响,采用ABAQUS有限元模拟结合内聚力模型(cohesive zone model,CZM),构建了包含纤维、基体及界面的三维细观结构模型,分析了复合材料的应力分布、裂纹扩展、...为研究SiC_(f)/Ti_(3)Al复合材料在单轴拉伸中产生的热残余应力对拉伸性能的影响,采用ABAQUS有限元模拟结合内聚力模型(cohesive zone model,CZM),构建了包含纤维、基体及界面的三维细观结构模型,分析了复合材料的应力分布、裂纹扩展、界面失效等。结果表明:在横向拉伸中,界面脱黏为主要失效机制,基体内等效应力的重新分配对整体性能起关键作用;在纵向拉伸中,热残余应力导致应力场非均匀分布并影响基体屈服,同时界面径向压应力有效减缓界面脱黏,延缓材料失效。研究结果揭示了热残余应力与界面特性对SiC_(f)/Ti_(3)Al复合材料横纵向拉伸性能的影响机制,为优化纤维增强金属基复合材料的设计与性能提升提供了理论支持。展开更多
文摘The titanium-based composites were synthesized by powder metallurgy method. The effects of composition and sintering temperature on the microstructure and properties of the titanium-based composites were investigated by X-ray diffraction, optical microscopy, scanning electron microscopy and mechanical properties tests. The results demonstrate that adding ZrO2 particles can improve the mechanical properties of powder metallurgy （P/M） titanium-based composites. The Ti composite with 4% （mole fraction） ZrO2 sintered at 1100 °C for 4 h shows an appropriate mechanical property with a relative density of 93.9%, a compressive strength of 1380 MPa （570 MPa higher than pure Ti） and good plasticity （an ultimate strain above 24%）.
文摘Reinforcement distribution tailoring has been proven effective in strengthening and toughening titanium matrix composites(TMCs).In this work,the analysis of the Ti64(Ti-6Al-4V)-B phase diagram indicated that B content dominates the TiB distribution.With this philosophy,B content regulation was applied to tailor homogeneous and network structures in Ti64-B composites fabricated via laser-directed energy deposition additive manufacturing(AM).The unique plate-like TiB attends inhomogeneous composites(Ti64–0.05B).However,in network composite(Ti64–0.25B),the TiB whisker(TiBw)arranges along priorβ-Ti grains with the same orientation.Moreover,the synergistic improvement of strength(988 MPa→1202 MPa),stiffness(106 GPa→116 GPa),hardness(325 HV→362 HV),and uniform elongation(5%→7.8%)were achieved.This work exhibited a balanced strength/ductility trade-off,which provides a good guide on microstructure tailoring.
文摘为研究SiC_(f)/Ti_(3)Al复合材料在单轴拉伸中产生的热残余应力对拉伸性能的影响,采用ABAQUS有限元模拟结合内聚力模型(cohesive zone model,CZM),构建了包含纤维、基体及界面的三维细观结构模型,分析了复合材料的应力分布、裂纹扩展、界面失效等。结果表明:在横向拉伸中,界面脱黏为主要失效机制,基体内等效应力的重新分配对整体性能起关键作用;在纵向拉伸中,热残余应力导致应力场非均匀分布并影响基体屈服,同时界面径向压应力有效减缓界面脱黏,延缓材料失效。研究结果揭示了热残余应力与界面特性对SiC_(f)/Ti_(3)Al复合材料横纵向拉伸性能的影响机制,为优化纤维增强金属基复合材料的设计与性能提升提供了理论支持。
