压制方式和烧结工艺对置氢Ti6Al4V粉末烧结体组织和性能的影响

Effects of compaction method and sintering process on microstructure and properties of Ti6Al4V alloy prepared by sintering of hydrogenerated powder

采用磁脉冲成形和模压成形2种方法对置氢Ti6Al4V粉末进行轴向压制,然后在保护气氛下烧结,研究压制方式和烧结工艺对烧结体真空退火后组织/性能的影响。结果表明：磁脉冲压实的不同氢含量粉末坯体烧结并真空退火后的相对密度、硬度和抗压强度分别比传统模压500 MPa下压制的高8%~13%、9~17 HRA和254~1 033 MPa。随着氢含量的增加,2种方式压制坯体的相对密度和硬度降低,当氢含量为0.01%时其值分别为97.38%和69.1 HRA;磁脉冲压实的坯体抗压强度先升高后降低,在氢含量0.32%时达到最大值1 965 MPa。随着烧结温度和时间的增加,模压成形烧结体的相对密度、硬度和抗压强度升高。烧结体真空退火后显微组织由α相和β相组成,磁脉冲成形的烧结体晶粒尺寸明显小于模压的晶粒尺寸。

Compaction experiments of hydrogenerated Ti6Al4V powder were carried out by magnetic pulse compaction（MPC） and die forming.And then,the compacts were sintered in a protective atmosphere.The effects of compaction method and sintering process on microstructure and mechanical properties were investigated.The relative density,hardness and compressive strength of vacuum annealed compacts prepared by MPC are 8%~13%,9~17 HRA and 254~ 1 033 MPa higher,respectively,than those prepared by traditional die forming at 500 MPa.With increasing hydrogen content,the relative density and hardness decrease basically,they are 97.38% and 69.1 HRA with 0.01% hydrogen;the compressive strength of vacuum annealed compacts prepared by MPC first increases and then decreases,it reaches the maximum value of 1 965 MPa with 0.32% hydrogen.The relative density,hardness and compressive strength increase with increasing sintering temperature and time.The grain size of vacuum annealed compacts pressed by MPC is obviously smaller than that of pressed by die forming.