The effects of heat treatment on the microstructure and mechanical properties of laser solid forming （LSF） Ti-6Al-4V alloy were investigated The influences of the temperature and time of solution treatment and aging...The effects of heat treatment on the microstructure and mechanical properties of laser solid forming （LSF） Ti-6Al-4V alloy were investigated The influences of the temperature and time of solution treatment and aging treatment were analyzed. The results show that the microstructure of LSFed samples consists of Widmanstatten α laths and a little acicular in columnar prior β grains with an average grain width of 300 μm, which grow epitaxiaUy from the substrate along the deposition direction （27）. Solution treatment had an important effect on the width, aspect ratio, and volmne fraction of primary and secondary a laths, and aging treatment mainly affects the aspect ratio and volume fraction of primary α laths and the width and volume fraction of secondary a laths. Globular a phase was first observed in LSFed samples when the samples were heat treated with solution treatment （950℃, 8 h/air cooling （AC）） or with solution treatment （950℃, 1 h/AC） and aging treatment （550℃, above 8 h/AC）, respectively. The coarsening and globularization mechanisms of a phase in LSFed Ti-6Al-4V alloy during heat treatment were presented. To obtain good integrated mechanical properties for LSFed Ti-6Al-4V alloys, an optimized heat treatment regimen was suggested.展开更多
对4种填料进行了挂膜试验,选择出3种挂膜性能良好的填料。并在自行开发的固定生物床反应器中,比较了这3种填料对炼油废水处理的效果。试验结果表明,F-Ⅲ型陶粒填料挂膜速度快,是一种理想的炼油废水处理生物填料。在炼油废水COD平均不大...对4种填料进行了挂膜试验,选择出3种挂膜性能良好的填料。并在自行开发的固定生物床反应器中,比较了这3种填料对炼油废水处理的效果。试验结果表明,F-Ⅲ型陶粒填料挂膜速度快,是一种理想的炼油废水处理生物填料。在炼油废水COD平均不大于700 mg/L,酚含量平均不大于100 mg/L,处理2 h的条件下,COD和酚的平均降解率分别可达68.5%和90.4%,COD的负荷及降解速率分别可达5.98 kg COD/m3.d和3.89 kg COD/m3.d。展开更多
基金supported by the Program for New Century Excellent Talents in Universities of China (No.NCET-06-0879)the National Natural Science Foundation of China (No.50331010)+2 种基金the Northwestern Polytechnical University Foundation of Fundamental Research (No.NPU-FFR-JC200808)the National Basic Research Program of China (No.2007CB613800)the Program of Introducing Talents of Discipline to Universities,China (No.08040)
文摘The effects of heat treatment on the microstructure and mechanical properties of laser solid forming （LSF） Ti-6Al-4V alloy were investigated The influences of the temperature and time of solution treatment and aging treatment were analyzed. The results show that the microstructure of LSFed samples consists of Widmanstatten α laths and a little acicular in columnar prior β grains with an average grain width of 300 μm, which grow epitaxiaUy from the substrate along the deposition direction （27）. Solution treatment had an important effect on the width, aspect ratio, and volmne fraction of primary and secondary a laths, and aging treatment mainly affects the aspect ratio and volume fraction of primary α laths and the width and volume fraction of secondary a laths. Globular a phase was first observed in LSFed samples when the samples were heat treated with solution treatment （950℃, 8 h/air cooling （AC）） or with solution treatment （950℃, 1 h/AC） and aging treatment （550℃, above 8 h/AC）, respectively. The coarsening and globularization mechanisms of a phase in LSFed Ti-6Al-4V alloy during heat treatment were presented. To obtain good integrated mechanical properties for LSFed Ti-6Al-4V alloys, an optimized heat treatment regimen was suggested.
文摘对4种填料进行了挂膜试验,选择出3种挂膜性能良好的填料。并在自行开发的固定生物床反应器中,比较了这3种填料对炼油废水处理的效果。试验结果表明,F-Ⅲ型陶粒填料挂膜速度快,是一种理想的炼油废水处理生物填料。在炼油废水COD平均不大于700 mg/L,酚含量平均不大于100 mg/L,处理2 h的条件下,COD和酚的平均降解率分别可达68.5%和90.4%,COD的负荷及降解速率分别可达5.98 kg COD/m3.d和3.89 kg COD/m3.d。
