Mechanical properties of a Mg-10 (vol.%)Ti composite
Mechanical properties of a Mg-10 (vol.%)Ti composite
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DOI：
10.1016/s0266-3538(03)00215-x
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发表时间：
2004-01-01
影响因子：
9.1
通讯作者：
Adeva, P
中科院分区：
文献类型：
--
作者：
Pérez, P;Garcés, G;Adeva, P
目前的工作涉及测定 Mg10(vol.%)Ti 复合材料在 25 至 300 摄氏度温度范围内的机械性能。该复合材料采用粉末冶金工艺，将纯钛粉和镁粉混合，然后进行热挤压。挤压后的钛增强材料呈现两种不同的形态：高度变形的细长颗粒和几乎不变形的粗颗粒。后者是由大的钛颗粒或钛颗粒聚集体产生的，它们在挤压过程中实际上不变形。另外，还存在小于1μm的细小氧化镁颗粒，装饰着镁颗粒的原始边界。通过拉伸和跳跃应变率测试研究了不同温度下的力学性能。尽管镁基体具有相对较大的晶粒尺寸，但该复合材料具有较高的强度（160 MPa）和较高的室温伸长率（8%），高于大多数陶瓷增强镁复合材料。在100-300℃温度范围内计算得到的应力指数约为13，表明变形以位错滑移为主。钛颗粒通过负载转移强化基体，负载转移通过钛颗粒的断裂来体现。此外，裂纹在整个硬钛颗粒中的进展导致延展性的增加，因为裂纹的扩展被延迟或什至被阻止。钛增强材料的有效性随着温度的升高而降低。 (C) 2003 Elsevier Ltd. 保留所有权利。
The present work deals with determination of the mechanical properties in the temperature range of 25 to 300 degreesC of a Mg10(vol.%)Ti composite. The composite material was processed through powder metallurgical route by mixing pure titanium and magnesium powders followed by hot extrusion. Titanium reinforcement after extrusion presents two different morphologies: highly deformed small elongated particles and practically non-deformed coarse particles. The latter results from large titanium particles or aggregates of Ti particles, which practically did not deform during the extrusion. In addition, fine magnesium oxide particles, less than 1 mum, decorating original boundaries of magnesium particles are present. The mechanical properties at different temperatures were studied by tensile and jump strain rate tests. Although the magnesium matrix shows a relatively large grain size, the composite shows a high strength (160 MPa), with a high elongation at room temperature (8%), higher than most of ceramic reinforced magnesium composites. The stress exponent calculated in the 100-300 degreesC temperature range was about 13 indicating that the deformation is dominated by dislocation slip. Titanium particles strengthen the matrix by load transfer that is manifested by fracture of titanium particles. Furthermore, progress of cracks throughout hard titanium particles results in an increase of the ductility, since propagation of the crack is delayed or even arrested. The effectiveness of titanium reinforcement decreases with increasing the temperature. (C) 2003 Elsevier Ltd. All rights reserved.