Principle of equal-channel angular pressing for the processing of ultra-fine grained materials
Principle of equal-channel angular pressing for the processing of ultra-fine grained materials
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DOI：
10.1016/1359-6462(96)00107-8
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发表时间：
1996-07-15
影响因子：
6
通讯作者：
Langdon, TG
中科院分区：
文献类型：
--
作者：
Iwahashi, Y;Wang, JT;Langdon, TG
近来相当大的兴趣集中在具有超细晶粒尺寸（通常<100 nm）的材料的加工上。这些材料可以通过各种技术制备，包括气体冷凝和随后在高真空下的原位固结、高能球磨和滑动磨损。可替代地，已经表明，可以在宽范围的材料（例如，纯金属、包括超合金的金属合金、金属间化合物、半导体）中通过使用等通道角（ECA）挤压或在高压下的扭转应变使这些材料经受非常高的塑性应变来产生亚微米晶粒结构。这些后一种方法通常得到的晶粒尺寸在{约}100- 200 nm的亚微米范围内，尽管有报道称晶粒尺寸小至{约}50 nm。在实践中，ECA压制是一种特别有吸引力的加工方法，因为它提供了生产没有任何残余孔隙的大体积样品的能力。
Considerable interest has centered recently on the processing of materials with ultra-fine grain sizes, typically <100 nm. These materials may be prepared by various techniques including gas condensation and subsequent in situ consolidation under high vacuum, high energy ball milling and sliding wear. Alternatively, it has been shown that submicrometer-grained structures may be produced in a wide range of materials (e.g. pure metals, metallic alloys including superalloys, intermetallics, semiconductors) by subjecting these materials to a very high plastic strain using either equal-channel angular (ECA) pressing or torsion straining under high pressure. These latter procedures usually give grain sizes in the submicrometer range of {approximately}100--200 nm although there are reports of grain sizes as small as {approximately}50 nm. In practice, ECA pressing is an especially attractive processing method because it provides the capability of producing large bulk samples which are free from any residual porosity.