【摘要】：通過(guò)常壓燒結(jié)法制備了氣孔率為53.43%的多孔氮化硅預(yù)制體,并利用擠壓鑄造法制備雙連續(xù)β-氮化硅增強(qiáng)鋁基復(fù)合材料,并研究了熱處理溫度對(duì)復(fù)合材料顯微組織和力學(xué)性能的影響。利用位錯(cuò)增殖強(qiáng)化理論和界面反應(yīng)理論分析復(fù)合材料的顯微組織和力學(xué)性能,結(jié)果表明,隨著熱處理溫度的升高,鋁合金基體發(fā)生位錯(cuò)增殖,β-氮化硅增強(qiáng)體和鋁合金基體的界面反應(yīng)程度增強(qiáng),復(fù)合材料的顯微硬度增高,斷裂韌性降低,彎曲強(qiáng)度先增加后降低,復(fù)合材料斷裂模式從沿晶韌性斷裂轉(zhuǎn)變?yōu)檠鼐Т嘈詳嗔�。�?dāng)熱處理溫度為850℃,復(fù)合材料的界面層厚度約為20~50 nm,其綜合力學(xué)性能達(dá)到最佳。
[Abstract]:Porous silicon nitride preforms with porosity of 53.43% were prepared by atmospheric pressure sintering, and double continuous silicon nitride reinforced aluminum matrix composites were prepared by squeeze casting. The effect of heat treatment temperature on the microstructure and mechanical properties of composites was studied. The microstructure and mechanical properties of the composites were analyzed by using dislocation multiplication strengthening theory and interfacial reaction theory. The results showed that dislocation proliferation occurred in aluminum alloy matrix with the increase of heat treatment temperature. The interfacial reaction between 尾 -Si _ 3N _ 4 reinforcements and aluminum alloy matrix was enhanced, the microhardness and fracture toughness of the composites were increased, and the bending strength first increased and then decreased. The fracture mode of composites changed from intergranular ductile fracture to intergranular brittle fracture. When the heat treatment temperature is 850 鈩，

本文編號(hào)：2369839