SiC_W＋B_4C_P／MB15镁基复合材料力学性能与微观结构

Properties and Structure of SiC_W+B4C_P/MB15 Magnesium Matrix Composite

对真空反压浸渍方法制备的挤压态ＳｉＣＷ＋Ｂ４ＣＰ／ＭＢ１５镁基复合材料及基体合金进行了一系列的力学性能测试，并用ＳＥＭ观察增强剂分布与断口形貌，用ＴＥＭ和ＥＤＳ方法对复合材料的界面结构进行分析。研究结果表明，上述复合材料同基体相比有更高的强度、弹性模量和比强度、比弹性模量。深浸蚀ＳＥＭ相分析表明均匀排布的晶须、颗粒起到很好的增强效果。复合材料的断口有晶须露头与韧窝存在，该复合材料具有一定的韧性；并在ＳｉＣ／ＭＢ１５界面上发现Ｚｎ析出相。

Sic+B4Cp/MB15 magnesium matrix composite is manufactured by vacuum pressure infiltrtion technique and the mechanical properties of the extruded-state composite are tested.SEM is helped to examine the distribution of the reinforcements and the tensile fracture surface of the composite.In addition,the interfacial structure is analyzed by means of TEM and EDS.SiC_W+B_4C_p/MB15 extruded-state composite shows much higher room temperature ultimate tensile strength and elastic modulus than those of MB15 matrix and other alloys,the specific UTS and the specific modulus also improve.The above excellent properties are related to the Well-distribution of the reinforcements in the matrix alloy.The whiskers'ends and toughing holes exist on the fracture surface,thus the composite pocesses a certain toughness.Deposition of Zn and the thick Mg-Zn precipatating phases are observed on the interface between SiC and MB15.