将主烧结曲线(MSC)理论应用于93W-5.6Ni-1.4Fe高比重合金的放电等离子烧结(SPS). 以加热速率100 ℃/min为临界点, 建立了2个不同加热速率阶段合金的主烧结曲线. 在2个不同加热速率阶段, 93W-5.6Ni-1.4Fe高比重合金的放电等离子烧结MSC曲线均可有效预测合金烧结全过程的致密化行为, 以及粉末压坯的收缩量和合金的最终烧结密度. 计算了93W-5.6Ni-1.4Fe高比重合金放电等离子烧结过程中的致密化函数c, 定量地证明了当加热速率大于100 ℃/min时, 随着温度升高, 合金的SPS致密化过程显著加快. 此外, 主烧结曲线理论计算得到的表观致密化激活能与采用Arrhenius公式计算所得到的致密化激活能基本一致.

Tungsten heavy alloys are used for a number of applications, including radiation shields, counter weights, electrical contacts, vibration dampeners and kinetic energy penetrators. The most common compositions consist of W along with some combination of Ni, Fe, or Cu. The alloys are usually fabricated by the conventional powder metallurgy technique, in which the elemental blended powders are first compacted and then followed by a high temperature sintering. An important processing goal for this alloy is to obtain a high density with fine grain size. It is therefore desirable to predict its densification behavior and final density. Recently, the master sintering curve (MSC) theory provides a better understanding of whole sintering process. In previous work, the densification and grain growth mechanisms during spark plasma sintering (SPS) of 93W-5.6Ni-1.4Fe heavy alloy were investigated. In this investigation, the master sintering curve approach was first extended theoretically to spark plasma sintering of 93W-5.6Ni-1.4Fe heavy alloy. Two master sintering curves of 93W-5.6Ni-1.4Fe heavy alloy in different heating rate stages (with heating rate of 100 ℃/min as division point) during SPS process were developed. Both of the master sintering curves can effectively predict the densification behavior of 93W-5.6Ni-1.4Fe heavy alloy during SPS process, as well as the shrinkage and final density. The calculated densification function c quantitatively shows that the densification process increases with temperature when heating rate is higher than 100 ℃/min. In addition, the apparent densification activation energies calculated by MSC are roughly identical to those obtained by Arrhenius method.