Ti颗粒增强混晶镁基复合材料组织性能

Microstructure and Properties of Ti Particle Reinforced Magnesium Matrix Composites with Mixed Crystal

以金属Ti颗粒作为增强相,通过高能球磨、机械混合及放电等离子烧结,获得微米晶纯Mg(MgMC)烧结坯和质量分数分别为3%、6%和9%的Ti颗粒弥散强化混晶镁基复合材料Ti_(p)/Mg_(MCS)。通过微观组织表征和压缩性能测试,研究了Ti颗粒含量对Ti_(p)/Mg_(MCS)复合材料致密性、基体组织形貌及第二相颗粒演变的影响规律,揭示了Ti_(p)/Mg_(MCS)复合材料在放电等离子烧结过程中的致密化行为,并阐明了Ti颗粒含量对复合材料室温压缩性能的影响。结果表明,Ti_(p)/Mg_(MCS)复合材料的基体呈混晶组织特征,增强体金属Ti_(p)与Mg基体结合良好,Ti/Mg复合界面不发生界面反应。随着Ti含量由3%提高至9%,复合材料的致密度呈减小趋势。研究证实,金属增强相Ti和基体混晶结构的引入可有效提高材料的压缩力学性能。相对于纯Mg_(MC)烧结坯,Ti含量为3%~9%的Ti_(p)/Mg_(MCS)复合材料的屈服强度、抗压强度和压缩失效应变分别提高了11.28%~38.17%、14.35%~16.56%和35.45%~54.97%。

Pure magnesium sintered billet with micron crystal(Mgmc)and Ti particle dispersion strengthened magnesium matrix composites with mixed crystal and various Ti_(p)content were prepared by high energy ball milling,mechanical mixing and spark plasma sintering.The influence of Ti_(p)content on the compactness,matrix microstructure and evolution of secondary phase particles was systematically investigated by microstructure characterization and compression tests.The densification behavior of Ti_(p)/Mg_(MCS) composites during spark plasma sintering process was revealed,and the effect of Ti_(p)content on the compressive properties of the composites was also clarified.The results indicate that the matrix of the Tip/Mg_(MCS) composites is characterized by mixed crystal,and well bonding between Ti_(p)reinforcement and Mg matrix is obtained without interfacial reaction at Ti/Mg compound interface.The density of composites is decreased with the increase of Ti content from 3%to 9%.It is proved that the compressive mechanical properties of Ti_(p)/Mg_(MCS) composites can be significantly improved with the introduction of Ti_(p) reinforcement and mixed crystal structure.The yield strength,compressive strength and failure strain of Ti/Mg_(MCS) composites with Ti contents from 3% to 9% are increased by 11.28%~38.17%,14.35%~16.56% and 35.45%~54.97%,respectively,compared with those of sintered Mg_(MC) billet.