放電プラズマ焼結法によるSCS-6/Ti-6Al-4V複合材料の引張および疲労強度

抄録

This study was undertaken to investigate the effect of spark plasma sintering (SPS) on the tensile and fatigue properties of laminates of SCS-6 SiC fiber-reinforced Ti-6Al-4V titanium matrix composites (TMC). The Ti-6Al-4V matrix and SCS-6 fiber mat were consolidated by spark plasma sintering at the temperature of 800, 900, and 1000°C and at the pressures of 30 and 60 MPa in vacuum. Tensile specimens of TMC were tested at room temperature, 400, 600, and 800°C. In addition, tensile properties of TMC were experimentally evaluated with 11 to 33% volume fraction of SCS-6. Fatigue tests of TMC were carried out at room temperature and 600°C. Specimens were examined after tensile and fatigue tests using SEM to characterize the fracture surface morphology. The fiber/matrix interactions were analyzed by energy dispersive x-ray spectroscopy (EDS).
TMC consolidated at 900°C and 60 MPa showed the highest strengths of 857 to 1679 MPa from room temperature to 800°C. The tensile strengths of TMC with volume fraction of fiber varied from 11 to 27% are approximately equal to the theoretical obtained from the rule-of-mixture model. TMC can sustain tensile stress level at or below 450 MPa at 600°C without fracture after more than 10⁷ cycles.