文章信息/Info

Title:

Research Progress on Nano�睞l2O3 Reinforced Metal Matrix Composites

作者:

馬思源; 郭強(qiáng); 張荻

上海交通大學(xué) 金屬基復(fù)合材料國(guó)家重點(diǎn)實(shí)驗(yàn)室

Author(s):

MA Siyuan;  GUO Qiang;  ZHANG Di

State Key Laboratory of Metal Matrix Composites, Shanghai Jiaotong University

關(guān)鍵詞:

納米Al2O3; 金屬基復(fù)合材料; 制備過(guò)程; 力學(xué)性能; 增強(qiáng)機(jī)制

Keywords:

nano-alumina;  metal matrix composites;  preparation methods;  mechanical properties;  enhancement mechanism

DOI:

10.7502/j.issn.1674-3962.201811011

文獻(xiàn)標(biāo)志碼:

A

摘要:

納米Al2O3顆粒具有優(yōu)異的力學(xué)性能，加入金屬中可以大幅提高材料的拉伸強(qiáng)度、屈服強(qiáng)度、硬度等常溫力學(xué)性能及高溫性能。在目前的實(shí)驗(yàn)室及工業(yè)生產(chǎn)中，制備納米Al2O3應(yīng)用最廣泛的是液相法，包括沉淀法、溶膠-凝膠法、水解法、微乳液法等。納米Al2O3增強(qiáng)金屬基復(fù)合材料可以通過(guò)外加法或原位法制備。外加法是在制備復(fù)合材料之前單獨(dú)合成納米Al2O3顆粒，結(jié)合粉末冶金、熔鑄等方法引入金屬基體，但往往容易出現(xiàn)納米增強(qiáng)體團(tuán)聚及增強(qiáng)體與基體界面結(jié)合不好。適當(dāng)?shù)募庸すに嚕�如機(jī)械合金化、摩擦攪拌工藝，能在一定程度上彌補(bǔ)這些缺點(diǎn)。原位法是使金屬Al發(fā)生氧化反應(yīng)，或基體中其他元素的氧化物與金屬Al發(fā)生鋁熱反應(yīng)生成Al2O3，再通過(guò)熱壓、擠出等致密化手段來(lái)制備納米Al2O3增強(qiáng)金屬基復(fù)合材料。原位法制備的復(fù)合材料往往增強(qiáng)相與基體界面結(jié)合更好，且納米Al2O3在基體中分布更均勻、分散。納米Al2O3在金屬基復(fù)合材料中增強(qiáng)機(jī)制主要有兩方面，一是Orowan機(jī)制，彌散在金屬晶粒內(nèi)部的納米Al2O3顆粒起到阻礙位錯(cuò)通過(guò)的作用；二是部分納米Al2O3分布在金屬晶界附近，阻止晶界移動(dòng)，從而阻止晶粒長(zhǎng)大。最后展望了納米Al2O3增強(qiáng)金屬基復(fù)合材料的發(fā)展前景，指出顯微組織結(jié)構(gòu)的構(gòu)型設(shè)計(jì)是進(jìn)一步提高這類(lèi)材料綜合力學(xué)性能的有效途徑。

Abstract:

Nano-alumina particles have excellent mechanical properties. When they are incorporated into metals, they can greatly improve the tensile strength, yield strength, hardness at room temperature and high-temperature properties of the matrix metals. At present, the most widely�瞮sed preparation method of nano-alumina in laboratory and industry are liquid phase methods, including precipitation method, sol-gel method, hydrolysis method, micro-emulsion method. Metal matrix composites (MMCs) reinforced by nano-alumina can be produced by ex-situ methods or in-situ methods. Ex-situ method is to add as�瞖xisting nano-alumina particles into the metal matrix by powder metallurgy or casting. Ex-situ method is prone to generate agglomeration of the nano�瞤articles and the interface adhesion between the reinforcement and the matrix may not be very strong. Appropriate processing techniques, such as mechanical alloying and friction stir processing, can mitigate these shortcomings. In-situ method is to synthesize the nano alumina particles during the process through the chemical reaction between oxygen�瞔ontaining contents with the aluminum matrix, followed by subsequent densification steps such as hot pressing and hot extrusion. MMCs prepared by in-situ methods tend to have better adhesion between the reinforcement phase and the matrix, and the nano-alumina is more uniformly distributed in the matrix. There are two main enhancement mechanisms of nano-alumina in MMCs, one is the Orowan mechanism, the other is some nano-alumina particles are distributed near grain boundaries, which can prevent grain boundary to move. At last, we provide some outlook on the future development of nano-alumina reinforced MMCs and suggest that careful architecture design on the microstructure of the composites may lead to the attainment of composites with superior mechanical properties.