SiCw/Al复合材料力学性能分散性

Mechanical Property Dispersity of SiCw/Al Metal Matrix Composites

金属基复合材料力学性能分散性影响其性能评价和广泛应用。本文研究了测量方法和组织缺陷对SiCw/Al复合材料力学性能统计分布规律的影响。结果表明,复合材料的弹性模量、强度和延伸率等性能均存在分散性,高性能数据出现频率最高,向低的性能值分散。弹性模量分散性受测量方法影响很大,直线段扩大法可以减小性能分散范围。强度和延伸率性能高的试样中发现夹铝区或未浸渗区等缺陷的概率远低于低性能试样,微观缺陷是造成强度和延伸率向低值方向分散的主要原因。为此减少组织缺陷并合理选择实验方法对复合材料的性能评价和应用是必要的。

Dispersity of the mechanical properties has a large effect on the evaluation and application of metal matrix composites. In this article, the mechanical property dispersity of SiCw/Al composites was studied, and the effects of the measurement method and microstructural defects on the dispersity were investigated. The results show that data of the modulus, strength and elongation distribute in a wide range with the highest data appearing at the highest frequency and then spreading towards low property directions. The measured data range of the modulus may be decreased by enlarged straight-line method （SEL）. In addition, microstructural defects of aluminum rich region and un-infiltrated region can be found more frequently on the fracture surface in the samples with a high property than that with a low property, showing that the existence of defects is the main reason that results in the dispersity of strength and elongation. So the removal of the defects and a proper experimental method are important for the property evaluation and application of composites.