论文标题
纳米晶铜 - 晶金合金的微结构，机械性能和老化行为
Microstructure, mechanical properties and aging behaviour of nanocrystalline copper-beryllium alloy
论文作者
论文摘要
据报道，通过严重的塑性变形Cu对粗粒和纳米结构的衰老动力学的复杂研究 - 据报道2 wt％合金。结果表明，粗粒合金的衰老会导致纳米化立方体中心立方体（BCC，CSCL-型 - 类型）半脱子颗粒的连续形成，并具有{220} cu // {200}立方体晶体学方向关系。这些颗粒产生了明显的内部应力场，并成为脱位滑行的障碍，导致硬度从95个Vickers硬度（HV）变化，用于溶解的合金对400 HV的年龄变化。严重的塑性变形导致形成平均晶粒尺寸为20 nm和390 HV的单相纳米化微观结构。发现这种晶粒大小是由晶界隔离略微驱动的。纳米晶合金的进一步衰老导致以前的Cu晶界的沉淀形成并跳过亚稳态。观察到年龄的纳米结构合金的显着年龄硬化，最大硬度为466 HV。机械测试结果表明，微观结构和进一步衰老对合金强度能力的强大影响，对于粗粒和纳米结构合金。还注意到纳米结构合金中的良好热稳定性。提供了立方相的硬度值的理论计算。结果表明，作为轻型合金元素，可以用于直接更换严重变形的铜合金的微观结构。
A complex study of aging kinetics for both coarse-grained and nanostructured by severe plastic deformation Cu -- 2 wt% Be alloy is reported. It is shown that aging of a coarse-grained alloy leads to continuous formation of nanosized CuBe body centred cubic (bcc, CsCl -- type) semi-coherent particles with the {220} Cu // {200} CuBe crystallographic orientation relationship. These particles created significant internal stress fields and became obstacles for dislocation glide that resulted in a change in the hardness from 95 Vickers hardness (HV) for the solubilized alloy to 400 HV for the aged one. The severe plastic deformation led to the formation of a single-phase nanograined microstructure with an average grain size of 20 nm and 390 HV. It was found that this grain size was slightly driven by grain boundary segregation. Further aging of the nanocrystalline alloy led to the discontinuous formation of precipitates on the former Cu grain boundaries and skipping of metastable phases. Significant age hardening with a maximum hardness of 466 HV for the aged nanostructured alloy was observed. Mechanical tests result revealed a strong influence of microstructure and further aging on strength capability of the alloy for both coarse-grained and nanostructured alloy. A good thermal stability in the nanostructured alloy was also noticed. Theoretical calculations of the hardness value for the CuBe phase are provided. It was shown that Be as a light alloying elements could be used for direct change of microstructure of severely deformed copper alloys.
