(哈爾濱工業(yè)大學 材料科學與工程學院， 哈爾濱 150001)
摘 要: 利用金相顯微鏡、 掃描電鏡、 透射電鏡和萬能拉伸試驗機等手段考察了粒度為0.3μm的Al2O3顆粒(體積分數(shù)為26%)增強6061Al復合材料在熱擠壓前后的顯微組織及室溫拉伸性能。 結(jié)果表明： 以10∶1的擠壓比熱擠壓后復合材料組織的均勻性得到了明顯改善， 顯微組織變化上呈現(xiàn)位錯由壓鑄態(tài)的近無位錯轉(zhuǎn)變?yōu)槲诲e有明顯增殖特征，并促進了時效析出； 復合材料擠壓材的抗拉強度、 屈服強度和延伸率較壓鑄材普遍提高； 熱擠壓沒有改變復合材料的斷裂機制， 由于擠壓后顆粒分布均勻等原因， 使復合材料的塑性得到改善。
關(guān)鍵字: 熱擠壓變形； Al2O3p/Al； 金屬基復合材料； 顯微組織；力學性能
sub-micro Al2O3p/Al composite
（School of Materials Science and Engineering，
Harbin Institute of Technology， Harbin 150001， China）
Abstract:The microstructure and mechanical properties of Al2O3p/6061Al composite reinforced by Al2O3 particle with size of 0.3μm(volume fraction 26%) before and after hot extrusion were investigated by OM， SEM， TEM and tensile test. The results show that, the microstructure of the composite after hot extrusion with the extrusion ratio of 10∶1 becomes more uniformly， and compared with the microstructure characteristic of nearly free dislocation before hot extrusion， more dislocations are found in the microstructure. The ultimate strength， yield strength and elongation of the composite are also increased after hot extrusion. The hot extrusion do not change the fracture mechanism of the composite and the plasticity is improved due to the evenly distributed particles after hot extrusion.
Key words: hot extrusion deformation； Al2O3p/Al； metal matrix composite； microstructure； mechanical properties
