(廣西科技大學(xué) 機(jī)械工程學(xué)院，柳州 545006)
摘 要: 采用光學(xué)金相顯微鏡、X射線衍射、拉伸試驗(yàn)、掃描電鏡、透射電鏡等技術(shù)，研究Cu含量對(duì)Al-Cu-Mg合金微觀組織及力學(xué)性能的影響。結(jié)果表明：鑄態(tài)Al-Cu-Mg合金中存在明顯的樹枝晶，沿晶界分布著大量塊狀S(Al2CuMg)和θ(Al2Cu)析出相。均勻化退火處理后，非平衡低熔點(diǎn)相基本熔入基體，晶間組織分布趨于均勻。大應(yīng)變軋制變形后，3種Al-Cu-Mg合金中均得到典型的纖維狀組織，合金中的第二相主要為S(Al2CuMg)相、θ(Al2Cu)相和T(Al20Cu2Mn3)相，沿晶界呈連續(xù)而均勻分布。經(jīng)時(shí)效處理后，3種Al-Cu-Mg合金均表現(xiàn)出優(yōu)異的綜合力學(xué)性能，Cu含量為2%(質(zhì)量分?jǐn)?shù))時(shí)，Al-Cu-Mg合金的抗拉強(qiáng)度、屈服強(qiáng)度和伸長(zhǎng)率分別為507 MPa、430 MPa和10.3%；合金的力學(xué)性能隨著Cu含量的增加呈遞增趨勢(shì)，當(dāng)Cu含量為4.5%時(shí)，Al-Cu-Mg合金的抗拉強(qiáng)度、屈服強(qiáng)度和伸長(zhǎng)率分別為644 MPa、547 MPa和10.5%。
關(guān)鍵字: Al-Cu-Mg合金；Cu含量；大應(yīng)變軋制；顯微組織；力學(xué)性能
（College of Mechanical Engineering, Guangxi University of Science and Technology, Liuzhou 545006）
Abstract:The effects of Cu content on microstructures and mechanical properties of Al-Cu-Mg alloy were investigated by optical microscopy, X-ray diffraction, tensile tester, scanning electron microscope and transmission electron microscope. The results show that there is obvious dendrite segregation in as-cast Al-Cu-Mg alloys, and a large number of massive S(Al2CuMg) and θ(Al2Cu) precipitates are distributed along the grain boundaries. After homogenization annealing treatment, the non-equilibrium low-melting phases are substantially dissolved into the matrix, and the intergranular structure distribution tends to be more uniform. After large strain rolling deformation, typical fibrous structures are obtained in the three kinds of Al-Cu-Mg alloys and the main secondary phases in the alloys are S(Al2CuMg), θ(Al2Cu) and T(Al20Cu2Mn3), which are continuous along the grain boundaries and evenly distributed. After aging treatment, all three kinds of Al-Cu-Mg alloys exhibit excellent comprehensive mechanical properties. When the Cu content is 2%(mass fraction), the tensile strength, yield strength and elongation are 507 MPa, 430 MPa and 10.3%, respectively. With the increase of Cu content, the mechanical properties of Al-Cu-Mg alloys show increasing trends, and the increase of Cu content has a significant effect on the mechanical properties of the alloy. When the Cu content is 4.5%, the tensile strength, yield strength, and the elongation of Al-Cu-Mg alloy are 644 MPa, 547 MPa, and 10.5%, respectively.
Key words: Al-Cu-Mg alloy; Cu content; large strain rolling; microstructure; mechanical property
