最新色国产精品精品视频,中文字幕日韩一区二区不卡,亚洲有码转帖,夜夜躁日日躁狠狠久久av,中国凸偷窥xxxx自由视频

In order to prepare high performance tungsten used as plasma face material, trace amount of ZrC was added to tungsten, and the densification behavior, properties and microstructure evolution of W-ZrC composites sintered at temperatures in the rang 1150 - 2000°C with flowing hydrogen atmosphere were investigated systematically. Results show that W-ZrC composite powders begin to form fine tungsten grains at 1300°C. The growth rate of grains is high at temperatures below 1600°C, and then slows down. The maximum relative density and tensile strength are 99.6% and 460MPa respectively under the optimum sintering process. ZrC particles are uniformly dispersed at grain boundaries and in grains interior with particle size from 0.1μm to 2 μm. Minor ZrC can effectively prevent the migration of grain boundaries and refine grain sizes from 100 μm of pure tungsten to 30 μm of W-ZrC composites. Minor ZrC can change the fracture mode and improve the strength and toughness of tungsten.