超细晶粒W-40%Cu合金的烧结和力学性能

Sintering and mechanical properties of nanoscaled W-40%Cu alloys

  • 摘要: 以纳米W,Cu粉末为原料,通过测定H2中热压烧结和无压烧结的收缩动力学曲线, 研究了纳米W-40%Cu化学混合粉末的致密化过程.对比了纳米W粉与常规Cu粉(-44μm) 的机械混合粉和纳米W-Cu化学混合粉的热压烧结致密化过程.测定了烧结合金在300℃和500℃下高温应力-应变曲线.实验结果表明:采用纳米W-40%Cu化学混合粉末在H2中无压烧结时最大收缩速率对应温度为980℃;1200℃烧结平均晶粒小于2μm,相对密度为97%.纳米W-Cu化学混合粉在H2热压烧结时最大收缩速率对应温度为930℃;1200℃烧结合金的平均晶粒为0.5μm,相对密度为98%.纳米W-Cu化学混合粉热压合金高温抗压强度比纳米W 与常规Cu粉的热压合金高.

     

    Abstract: The densification of nanoscaled W-Cu powder was investigated through measurements of the shrinkage kinetic curves in hot pressing and hydrogen sintering and compared with that of nanoscaled W powder and traditional Cu powder. The resulted alloys were subjected to hot compression tests at 300℃ and 500℃ to obtain their stress-strain curves. It is indicated that the temperature corresponding to the highest shrinkage rate of nanoscaled W-Cu powder is 980℃ in hydrogen sintering. After sintering at 1200℃, the mean grain size of W phase is less than 2 μm, and the relative density of the alloy is 97%. In hot pressing, however the corresponding temperatures is 930℃. The mean grain size of W phase in the hot pressed alloy from nanoscaled W-Cu powder is 0.5μm at 1 200℃, and its relative density is 98%. The results of hot compression tests at 300℃ and 500℃ showed that the high-temperature strength of the ultrafine grained W-Cu alloy is higher than that of the alloy sintered from nanoscaled W powder and traditional Cu powder.

     

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