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以高能球磨法制备的93W-4.9Ni-2.1Fe复合粉末为原料,采用放电等离子烧结技术制备93W--4.9Ni-2.1Fe合金,研究了烧结温度对钨合金微观组织及性能的影响.采用扫描电镜对试样的断口进行观察,采用能量色散谱仪对合金的组元进行成分分析.结果表明:①烧结温度对合金的性能有显著的影响,在1 350℃时钨合金的抗拉强度达到一个极大值,为981 MPa,此时钨合金的相对密度和W晶粒的尺寸分别为98.9%和5μm;②当烧结温度达到1375℃时,合金中Ni元素开始挥发,随着温度的快速上升,合金中Ni元素的挥发不断加剧,当烧结温度升高至1425℃时合金中Ni元素已完全挥发;③合金的断裂方式随着烧结温度的升高发生显著的变化,当烧结温度升至1350℃时钨合金的断裂方式由W晶粒界面分离向W-W、W-黏结相界面断裂转变,而当烧结温度超过此温度时钨合金的断裂方式又转变为W晶粒的沿晶脆性断裂;④SPS快速烧结能够有效抑制W晶粒的长大,促进钨合金的细晶强化作用.
The 93W-4.9Ni-2.1Fe alloy prepared by high-energy ball milling was prepared by spark plasma sintering and the effect of sintering temperature on the microstructure and properties of tungsten alloy was investigated. The fracture of the sample was observed by electron microscope and the composition of the alloy was analyzed by energy dispersive spectroscopy.The results showed that: ① sintering temperature had a significant effect on the properties of the alloy, the tensile strength of the tungsten alloy reached at 1 350 ℃ A maximum value of 981 MPa. At this time, the relative density of tungsten alloy and the size of the W grain are 98.9% and 5μm, respectively. ② When the sintering temperature reaches 1375 ℃, the Ni element in the alloy begins to volatilize. With the rapid temperature The Ni element in the alloy volatilized continuously. When the sintering temperature was increased to 1425 ℃, the Ni element in the alloy was completely volatilized. ③ The fracture mode of the alloy changed significantly with the increase of the sintering temperature. When the sintering temperature rose to At 1350 ℃, the fracture mode of tungsten alloy is changed from the interface of W grain to the interface of WW and W-bonded phase, and the fracture mode of tungsten alloy transforms to the brittle fracture along W crystal when the sintering temperature exceeds this temperature. ④ S PS rapid sintering can effectively inhibit the growth of W grains and promote the fine grain strengthening effect of tungsten alloy.