添加MgH2對機械合金化Al-12%Sn合金組織和性能的影響

添加MgH2對機械合金化Al-12%Sn合金組織和性能的影響Effect of MgH2 on microstructure and properties of MA Al-12%Sn alloy

利用機械合金化方法制備出Al-12%Sn-x%MgH2(質(zhì)量分?jǐn)?shù))合金粉末，然后將其壓制成型并進(jìn)行燒結(jié)，得到合金塊體；并運用X射線衍射儀、掃描電鏡、拉伸機和摩擦磨損實驗機研究添加MgH2對Al-12%Sn合金組織結(jié)構(gòu)和性能的影響。結(jié)果表明：添加MgH2能使合金中的Sn更加細(xì)小均勻分布在Al基體上，同時能破壞Al顆粒表面的氧化膜，增加Al-12%Sn合金的燒結(jié)活性。隨著MgH2含量的增加，合金的致密度和拉伸強度顯著提高。但當(dāng)MgH2過量時，會生成硬脆相Mg2Sn，造成基體Sn相的缺失，并降低合金的力學(xué)性能。此外，添加適量的MgH2對Al-12%Sn合金的耐磨性也有明顯改善。當(dāng)MgH2添加量為0.8%時，合金具有最優(yōu)的綜合力學(xué)性能和摩擦磨損性能。

The mechanical alloying(MA) was used to prepare Al-12%Sn-x%MgH2 (mass fraction) alloy powder. Then the bulk alloy was obtained by a combination of cold pressing and conventional powder sintering. The effects of MgH2 addition on the microstructure and properties of Al-12%Sn were investigated by XRD, SEM, mechanical properties tester and wearing tester. The results show that MgH2 addition can achieve Sn phase homogenously distribution in Al matrix. It also can disrupt the oxide film covered on Al particles and increase the sintering activity of Al-12%Sn alloy. With the MgH2 addition increasing, the relative density and tensile strength of Al-12%Sn alloy improve significantly. But excessive MgH2 addition will bring about brittle phase Mg2Sn, which not only causes the poor of Sn phase in the matrix but also leads to the deterioration of the alloys. In addition, MgH2 addition can also improve the wear properties of Al-12%Sn alloy. When the MgH2 content is 0.8%, Al-12%Sn alloy exhibits the best mechanical properties and wear properties.

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