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Al-Pb alloy was modified by high current pulsed electron beam and the microstructure, hardness and tribological characteristics were characterized by scanning electron microscopy, electronic microanalysis probe microanalysis, Knoop hardness indentation and pin-on-disc type wear testing machine. The results show that the microstructure and hardness can be greatly improved, and the modification layer consists of a molten zone, an overlapped zone of heat-affected and quasistatic thermal stress-affected zone and a transition zone followed by the substrate. The tribological properties of high current pulsed electron beam irradiated Al-Pb alloy are correspondingly improved largely. Optical observation and scanning electron microscopy analysis reveal that the low wear rate and lowest level in coefficient of friction at high load level for irradiated Al-Pb alloy are due to the formation of a lubricious tribolayer covering the worn surface, which is a mixture of Al2O3, Pb3O4 and silicate. The wear mode varies from oxidative wear at low load to film spalling at high load and, finally, adhesive wear. 相似文献
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压铸镁合金AZ91D高周疲劳性能研究 总被引:2,自引:3,他引:2
研究了压铸镁合金AZ91D在应力比R=0.1条件下的高周疲劳性能。结果表明:AZ91D压铸镁合金的室温条件疲劳强度在应力比R=0.1时大约相当于其抗拉强度的44%;AZ91D合金内部的一些缺陷如夹杂等,容易引起应力集中,从而导致裂纹的萌生;AZ91D合金的疲劳断口可以观察到3个典型区域:疲劳源区、疲劳裂纹扩展区和瞬断区。疲劳裂纹扩展区的疲劳裂纹不明显,疲劳断口呈现出准解理断口的形貌。 相似文献
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Recently , magnesiumalloy has become a very at-tractive material because of its lowdensity ,high spe-cific strength, and easy recyclability compared withother metals[1].As alight structural material ,recentlythere has been a significantincreaseinthe use of mag-nesiumalloy for automobiles ,aerospace components ,computers , mobile phones , and household equip-ments[2 ,3]. Mg-Al-Zn (AZ91D) alloyis the most wide-ly used die-cast magnesiumalloyin automotive applica-tions due toits excellent casta… 相似文献
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随着教学改革的不断深入,现行的高等学校教材供应机制已越来越不能满足和适应形势发展的要求,通过分析其原因,提出了改革当前高等学校教材供应机制的若干举措。 相似文献
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研究了在无润滑条件下,压铸铝合金A lSi9Cu3的铁金属间化合物对高速钢刀具钻削磨损特性的影响。结果表明:当合金中铁的质量分数较低时(w(Fe)<0.6%),铁金属间化合物以细小的多边形形状铁相为主,刀具后刀面磨损机制主要为塑性变形磨损,磨损量较大;当0.6%0.8%时,汉字状和多边形状铁相明显增多,呈薄片晶状的β相A l5FeSi出现,磨粒磨损成为主要的磨损机制,磨损量变大。粘着磨损和磨粒磨损共存的磨损机制是钻削压铸铝合金刀具合理的磨损机制。 相似文献
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简介了WAP协议并设计了实现该协议的总体方案,然后用petri网的有关理论对WTP层进行了描述,最后具体实现了WTP层. 相似文献
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采用正交试验的方法对压铸镁合金AZ91D进行了钻削试验,用多元线性回归法对试验结果进行了处理,建立了压铸镁合金AZ91D的钻削力与扭矩的经验公式。由经验公式可以确定:对钻削力和扭矩影响最大的是钻头直径 d,进给量 f次之,切削速度 v的影响最小。因此在实际生产中可以采用提高转速的办法来提高加工效率,减少能耗。 相似文献