论文部分内容阅读
利用水蒸气与W粉颗粒的氧化-气化反应制备连续孔隙度梯度的多孔W坯,考察了W粉的粒度组成、反应温度和时间对W坯孔隙度梯度的影响。釆用金相显微镜观察试样的金相显微组织,并运用图像分析软件测量其孔隙的体积分数。结果表明:通过氧化-气化法能制备连续梯度的多孔W坯,其孔隙度从表层到芯部逐渐降低。细W粉对构造孔隙非常有利,含有更多细W粉的W坯拥有更大的孔隙度和孔隙梯度;较高的反应温度也能促使W坯形成更大的孔隙度和孔隙梯度;反应时间越长,得到的W坯孔隙度越大,形成的孔隙梯度区域也越大。此外,试样表层孔隙尺寸大于芯部孔隙尺寸。
The porous W billet with continuous porosity gradient was prepared by the oxidation-gasification reaction of water vapor and W powder particles. The influence of the particle size composition, reaction temperature and time of W powder on the porosity gradient of W billet was investigated. Preclude the use of metallographic microscope to observe the microstructure of the sample, and the use of image analysis software to measure the pore volume fraction. The results show that the porosity of continuous porous W blank can be reduced gradually from the surface layer to the core by oxidation - gasification method. The fine W powder is very favorable for the structural porosity, the W billets containing more fine W powder have greater porosity and pore gradient; the higher reaction temperature can also cause the W billet to form larger porosity and pore gradient; the reaction time The longer the porosity of the resulting W billet, the greater the gradient area of the pores formed. In addition, the sample surface pore size is larger than the core pore size.