International Journal of Refractory Metals & Hard Materials ( IF 3.6 ) Pub Date : 2022-07-06 , DOI: 10.1016/j.ijrmhm.2022.105940 Randall M. German
Tungsten heavy alloys are fabricated using liquid phase sintering to form inertial, electrical, radiation, or structural components. The compositions, initially developed a century ago, are based on various W-Ni-(Fe/Cu/Co/Mo) alloys. Two classes, and W-Ni-Fe and W-Ni-Cu, remain the most popular. Nickel is key to sintering densification, producing the majority of sintering shrinkage prior to liquid formation. Sintering densification and distortion depend on the gravitational environment. Normal gravity induces distortion after densification, while sintering in microgravity fails to reach full density yet distorts. Mechanical properties are adjustable via changes to the composition, sintering cycle, or post-sintering treatment. Increased strength, with a loss of ductility, comes with post-sintering deformation and aging treatments. As shown here, a range of mechanical property combinations are possible. Processing options designed to improve strength invariably result in a loss of ductility, and vice versa. Peak property combinations are attainable over a broad tungsten content range, reflecting convergence to a self-similar microstructure.
中文翻译:
烧结钨重合金:微观结构、强度、致密化和变形回顾
钨重合金是使用液相烧结制造的,以形成惯性、电气、辐射或结构部件。这些成分最初是在一个世纪前开发的,基于各种 W-Ni-(Fe/Cu/Co/Mo) 合金。两个类别,W-Ni-Fe 和 W-Ni-Cu,仍然是最受欢迎的。镍是烧结致密化的关键,在液体形成之前产生大部分烧结收缩。烧结致密化和变形取决于重力环境。正常重力在致密化后会引起变形,而在微重力下烧结未能达到全密度而变形。机械性能可通过改变成分、烧结周期或烧结后处理来调整。烧结后变形和时效处理伴随着强度的增加,延展性的损失。如图所示,一系列机械性能组合是可能的。旨在提高强度的加工选项总是会导致延展性损失,反之亦然。峰值性能组合可在较宽的钨含量范围内实现,反映收敛到自相似微结构。