93W-4.9Ni-2.1Fe合金的力学性能及断裂行为研究

Study on Mechanical Properties and Fracture Behavior of 93W-4.9Ni-2.1Fe Tungsten Heavy Alloy

以93W-4.9Ni-2.1Fe高比重钨合金为研究对象,系统研究了不同粒度钨粉制备的93W-4.9Ni-2.1Fe合金在1415~1550℃温度下烧结后的力学性能,并分析了热处理工艺对钨合金力学性能的影响及钨合金的断裂行为。结果表明:随着烧结温度的升高,烧结态钨合金的力学性能均表现为先增大后减小再增大的规律,在1500~1510℃烧结时钨合金的力学性能出现突然下降;6.0μm粗钨粉制备的钨合金的力学性能整体比相同烧结温度下细钨粉制备的钨合金高;93W-4.9Ni-2.1Fe合金在氢气气氛中高温烧结后再在氮气气氛下进行固溶+淬火热处理可以显著提高力学性能;钨合金的力学性能与其断裂行为有关,断口形貌为钨晶粒高度的穿晶解理断裂和粘结相延性断裂时合金表现为高强韧性。

The paper took the 93W-4.9Ni-2.1Fe tungsten heavy alloys as the subject investigated and systematically studied the mechanical properties of the alloy prepared by powders of different particle sizes sintering at temperatures ranging from 1 415 to 1 550 ℃. Effect of heat treatment process on mechanical properties and the fracture behavior of the alloy were analyzed. The results indicated that with increase in the sintering temperatures, the mechanical properties of sintered tungsten alloys revealed a trend of increasing first, then decreasing and finally increasing, a sudden decrease showing up during the temperature range of 1 500~1 510 ℃. However, the mechanical properties of the tungsten alloys prepared by 6.0 μm particle size tungsten powders are higher than those prepared by finer tungsten powders at the same sintering temperature, which could be significantly improved by exposing to high temperature sintering and then putting it in nitrogen atmosphere to start solid solution and quench. The study showed that mechanical properties of tungsten alloys are related to their fracture behavior. The tungsten grain height being transgranular cleavage fracture and bond phase ductile fracture, high strengthness and toughness would be represented.