復(fù)合材料的微觀組織及力學(xué)性能
(江蘇大學(xué) 材料科學(xué)與工程學(xué)院，鎮(zhèn)江 212013)
摘 要: 采用熔體反應(yīng)法，以Al-ZrSiO4為反應(yīng)體系，在反應(yīng)過程中施加脈沖磁場，原位合成Al3Zr和Al2O3顆粒增強(qiáng)鋁基復(fù)合材料。X射線衍射儀(XRD)、掃描電鏡(SEM)和電子探針(EPMA)分析表明：脈沖磁場作用下，原位合成的顆粒細(xì)小，尺寸為1~3 μm，且彌散分布于基體中；隨外加脈沖磁場強(qiáng)度的增大，反應(yīng)生成的增強(qiáng)顆粒變得更加細(xì)小，分布更均勻。拉伸實(shí)驗(yàn)結(jié)果表明：脈沖磁場作用下原位合成復(fù)合材料的抗拉強(qiáng)度隨著脈沖磁場強(qiáng)度的增大而升高，當(dāng)磁場強(qiáng)度為0.05 T時(shí)，復(fù)合材料的抗拉強(qiáng)度比未施加脈沖磁場的復(fù)合材料提高28％；伸長率隨磁場強(qiáng)度的增大略微下降。拉伸斷口形貌分析表明：脈沖磁場作用下復(fù)合材料斷口形貌中的韌窩和撕裂紋大大減少，但仍屬于塑性斷裂。
關(guān)鍵字: 鋁基復(fù)合材料；脈沖磁場；原位合成；凝固組織；力學(xué)性能
Al2O3+Al3Zr)p/Al composites in-situ synthesized under
pulsed magnetic field
（School of Materials Science and Engineering, Jiangsu University,
Zhenjiang 212013, China）
Abstract:In-situ Al3Zr and Al2O3 particles reinforced aluminum matrix composites were synthesized by direct melt reaction method under pulsed magnetic field in Al-ZrSiO4 system. It is found by XRD, SEM and EPMA that the particles in-situ synthesized under pulsed magnetic field are fine and well distributed in the Al matrix, the size of Al3Zr and Al2O3 particles is in the range of 1?3 μm. With increasing pulsed magnetic intensity, the size and distribution of in-situ particles in the matrix become refiner and more homogenous. It is found that the ultimate tensile strength of (Al2O3+Al3Zr)p/Al composites is improved with increasing pulsed magnetic intensity, whereas the elongation of these composites goes down. Compared with the composites synthesized under zero pulsed magnetic field, the tensile strength of the composites synthesized is increased by 28% when the pulsed magnetic intensity is 0.05 T. The fracture morphology indicates that the dimple and torn grain of the composites synthesized under pulsed magnetic field are less than those under zero magnetic field, but it still belongs to plastic fracture.
Key words: Al-based composites; pulsed magnetic field; in-situ synthesis; solidification microstructure; mechanical property
