(中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 基于修正的剪切滯后模型、Eshelby等效夾雜理論以及Weibull統(tǒng)計(jì)分布，發(fā)展SiC增強(qiáng)鋁基復(fù)合材料屈服應(yīng)力的本構(gòu)模型。選取多種鋁合金，包括工業(yè)純鋁、Al-Mg-Si合金、Al-Cu-Mg合金以及Al-Zn-Mg 合金，作為復(fù)合材料的基體材料進(jìn)行屈服應(yīng)力的測(cè)試，以驗(yàn)證模型的準(zhǔn)確性。模型考慮變形過(guò)程中SiC顆粒失效(包括顆粒脫粘和顆粒斷裂)對(duì)復(fù)合材料屈服應(yīng)力的影響。結(jié)果表明：復(fù)合材料的屈服應(yīng)力隨著SiC顆粒體積分?jǐn)?shù)的增加而增加，但隨著SiC顆粒尺寸的增加而降低；該力學(xué)模型比傳統(tǒng)的修正剪切滯后模型更加準(zhǔn)確，這表明SiC顆粒失效對(duì)復(fù)合材料的屈服應(yīng)力產(chǎn)生重要的影響。
關(guān)鍵字: SiC/Al復(fù)合材料；屈服應(yīng)力；載荷轉(zhuǎn)移；Weibull統(tǒng)計(jì)
SiC reinforced aluminum alloy composites
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:A constitutive model for the yield stress of SiC reinforced aluminum alloy composites was developed based on the modified shear lag model, Eshelby’s equivalent inclusion approach and Weibull statistics. Several types of aluminum alloys including industry pure aluminum, Al-Mg-Si alloy, Al-Cu-Mg alloy and Al-Zn-Mg alloy were chosen as the matrix materials to verify the accuracy of the model. The failure of the SiC particles including particle debonding and cracking on the yield stress of composites during the deformation process was considered in the model. The results show that the yield stress of the composites increases with increasing volume fraction of SiC particles, but it decreases with increasing size of the SiC particles. The prediction of the present developed constitutive model agrees much better with the experimental data than the traditional modified shear lag model, which indicates that the failure of SiC particles has important effect on the yield stress of the SiC reinforced aluminum alloy composites.
Key words: SiC/Al composites; yield stress; load transferring; Weibull statistics
