(哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院， 哈爾濱 150001)
摘 要: 利用金相顯微鏡、 掃描電鏡、 透射電鏡和萬(wàn)能拉伸試驗(yàn)機(jī)等手段考察了粒度為0.3μm的Al2O3顆粒(體積分?jǐn)?shù)為26%)增強(qiáng)6061Al復(fù)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(fù)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(cuò)由壓鑄態(tài)的近無(wú)位錯(cuò)轉(zhuǎn)變?yōu)槲诲e(cuò)有明顯增殖特征，并促進(jìn)了時(shí)效析出； 復(fù)合材料擠壓材的抗拉強(qiáng)度、 屈服強(qiáng)度和延伸率較壓鑄材普遍提高； 熱擠壓沒(méi)有改變復(fù)合材料的斷裂機(jī)制， 由于擠壓后顆粒分布均勻等原因， 使復(fù)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(fù)合材料； 顯微組織；力學(xué)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
