球磨和液相烧结制备W-Ni-Fe合金的组织和力学性能

Microstructure and Properties of 93W-4.6Ni-2.4Fe Prepared by Ball-Milling and Liquid Phase Sintering

摘要:

为了制备出优异、经济友好的钨重合金，在1450~1510 ℃的烧结温度范围内，通过球磨和液相烧结制备了93W-4.6Ni-2.4Fe（质量分数）合金。进一步研究了试样的微观结构和断裂模式。结果表明，在不同烧结温度下，烧结的试样表现出相似的两相显微结构和韧性断裂模式。随着烧结温度的升高，钨颗粒尺寸也逐渐增大。当烧结温度达到或超过1480 ℃时，合金相对密度达到99.0%以上。1480 ℃烧结时可获得具有最佳抗拉伸强度（940 MPa）和延伸率（32.6%）组合的试样。在1480 ℃下烧结的试样具有优异的延展性，这与γ相的网络结构、韧窝的均匀分布以及两相的协同作用有关。试样的高强度归因于细化的钨颗粒尺寸和球形的钨颗粒。

Abstract:

In order to produce economical tungsten alloys with superior mechanical properties, 93W-4.6Ni-2.4Fe (wt%) tungsten heavy alloys were fabricated by ball milling and liquid phase sintering at a temperature range of 1450?1510 °C. The microstructure and the fracture modes of the specimens were examined. Results show that the specimens sintered at different temperatures display similar dual-phase microstructure and ductile fracture modes. With the increase in sintering temperature, the tungsten particle size also gradually grows. At the temperatures above 1480 °C, the relative density reaches above 99.0%. The optimal sintering temperature of the specimen with the best tensile strength (940 MPa) and elongation (32.6%) combination is determined to be 1480 °C. The excellent ductility of the specimen sintered at 1480 °C is associated with the network structure of γ phase, the uniform distribution of dimples and the synergistic effect of these two phases. The high strength of the specimen is attributed to the refined tungsten particle size and the spherical tungsten particles.