GNPs-Cu/Ti6Al4V复合材料热压烧结工艺优化及组织性能

Optimization of hot pressing sintering process and microstructure and properties of GNPs-Cu/Ti6Al4V composites

以TC4钛合金粉为基体,石墨烯(GNPs)为增强相,采用真空热压法制备了质量分数为0.3%的GNPs-Cu/Ti6Al4V复合材料。通过正交试验探讨了烧结温度、压力、保温时间对复合材料相对密度、显微硬度和抗压强度的影响。结果表明:烧结温度是影响复合材料相对密度、显微硬度和抗压强度的关键因素,压力和保温时间对其影响较小。最优的烧结工艺为温度1150℃、压力35 MPa和保温时间40 min,此时复合材料的相对密度、显微硬度和抗压强度最佳,分别为99.34%,585.4 HV0.1和2382 MPa。GNPs-Cu/Ti6Al4V复合材料中主要除α-Ti和β-Ti外,还存在TiC和Ti_(2)Cu相,在其压缩断口有较完整GNPs存在。

Using TC4 titanium alloy powder as matrix and graphene(GNPs)as reinforcement,GNPs-Cu/Ti6Al4V composites with GNPs content of 0.3 mass fraction% were prepared by vacuum hot pressing,and effects of sintering temperature,pressure and holding time on relative density,microhardness and compressive strength of the composites were investigated by orthogonal test.The results show that the sintering temperature is the key factor affecting the relative density,microhardness and compressive strength of the composites,while pressure and holding time have little effect on it.The optimal sintering process of the composites is the sintering temperature of 1150℃,pressure of 35 MPa and holding time of 40 min,and the relative density,microhardness and compressive strength of the composites are 99.34%,585.4 HV0.1 and 2382 MPa,respectively.The phases of the GNPs-Cu/Ti6Al4V composites are mainly α-Ti and β-Ti phases and a small amount of TiC and Ti_(2)Cu phases,and the complete GNPs can be observed on its fracture surface.