The effect of sintering temperature(1073?1373 K)on the structural and tribological properties of nanostructured ballmilledβ-type Ti?15Mo samples was investigated.The prepared samples were characterized using various ...The effect of sintering temperature(1073?1373 K)on the structural and tribological properties of nanostructured ballmilledβ-type Ti?15Mo samples was investigated.The prepared samples were characterized using various apperatus such as X-ray diffractometer,scanning electron microscope(SEM)and ball-on-plate type oscillating tribometer.Wear tests were conducted under different applied loads(2,8 and 16 N).Structural results showed that the mean pore and crystallite size continuously decreased with increasing sintering temperature to reach the lowest values of 4 nm and 29 nm at 1373 K,respectively.The relative density of the sintered sample at 1373 K was as high as 97.0%.Moreover,a higher sintering temperature resulted in higher relative density,greater hardness and elastic modulus of the sample.It was observed that both the friction coefficient and wear rate were lower in the sample sintered at 1373 K which was attributed to the closed porosity.展开更多
In order to overcome the embrittlement of metastable titanium alloys caused by the precipitation ofωiso phase during aging,regulation of isothermalωprecipitation was investigated in Ti−15Mo alloy.The results show th...In order to overcome the embrittlement of metastable titanium alloys caused by the precipitation ofωiso phase during aging,regulation of isothermalωprecipitation was investigated in Ti−15Mo alloy.The results show that the sample is brittle when direct aging(A)is applied at 350℃for 1 h after solution treatment(ST).If pre-deformation(D)is performed on the ST sample to induce{332}twins and secondaryα″phase,subsequent aging at 350℃(STDA350)improves the strength to 931 MPa with a good ductility of about 20%maintained.However,when aging is performed at 400℃or 450℃(STDA400/450),the strength can be further improved,but the ductility is dramatically reduced.Atomic-scale characterizations show that the partial collapse ofωphase in the STDA350 sample effectively eliminates aging-induced embrittlement,but complete collapse leads to poor ductility in the STDA400/450 sample.展开更多
基金the financial support from the Fundamental Research Program of Shanxi Province,China(No.202203021211130)the National Natural Science Foundation of China(Nos.51801132,52075359)。
文摘The effect of sintering temperature(1073?1373 K)on the structural and tribological properties of nanostructured ballmilledβ-type Ti?15Mo samples was investigated.The prepared samples were characterized using various apperatus such as X-ray diffractometer,scanning electron microscope(SEM)and ball-on-plate type oscillating tribometer.Wear tests were conducted under different applied loads(2,8 and 16 N).Structural results showed that the mean pore and crystallite size continuously decreased with increasing sintering temperature to reach the lowest values of 4 nm and 29 nm at 1373 K,respectively.The relative density of the sintered sample at 1373 K was as high as 97.0%.Moreover,a higher sintering temperature resulted in higher relative density,greater hardness and elastic modulus of the sample.It was observed that both the friction coefficient and wear rate were lower in the sample sintered at 1373 K which was attributed to the closed porosity.
基金the financial support from the National Natural Science Foundation of China (No. 52374380)the China Postdoctoral Science Foundation (Nos. 2023M730234, 2024T171126)。
文摘In order to overcome the embrittlement of metastable titanium alloys caused by the precipitation ofωiso phase during aging,regulation of isothermalωprecipitation was investigated in Ti−15Mo alloy.The results show that the sample is brittle when direct aging(A)is applied at 350℃for 1 h after solution treatment(ST).If pre-deformation(D)is performed on the ST sample to induce{332}twins and secondaryα″phase,subsequent aging at 350℃(STDA350)improves the strength to 931 MPa with a good ductility of about 20%maintained.However,when aging is performed at 400℃or 450℃(STDA400/450),the strength can be further improved,but the ductility is dramatically reduced.Atomic-scale characterizations show that the partial collapse ofωphase in the STDA350 sample effectively eliminates aging-induced embrittlement,but complete collapse leads to poor ductility in the STDA400/450 sample.
