铝硅合金活塞表面无色化学氧化技术

本文介绍了本公司提高铝硅合金活塞耐蚀性能的无色化学氧化工艺及其主要工序的溶液配方、工艺条件、操作要求 ;试验分析了无色化学氧化溶液各因素对氧化膜耐蚀性的影响和氧化膜的抗蚀性能 ;采用此工艺既提高了铝硅合金活塞耐蚀性 ,又保持了铝基光泽 ,工艺简单 ,效率高 。

压铸铝合金防护技术在装备中的应用

介绍了压铸铝合金镀锌彩钝和无色化学氧化工艺。分析了镀锌层附着力差、耐蚀性差的原因,并给出了解决办法。经测试,镀锌彩钝膜附着力和耐蚀性均合格,压铸铝合金无色化学氧化膜的耐蚀性合格。

Nanoscale graphene oxide sheets as highly efficient carbocatalysts in green oxidation of benzylic alcohols and aromatic aldehydes

Nanoscale graphene oxide(NGO)sheets were synthesized and used as carbocatalysts for effectiveoxidation of benzylic alcohols and aromatic aldehydes.For oxidation of alcohols in the presence ofH2O2at80°C,the NGOs(20%mass fraction)as carbocatalysts showed selectivity toward aldehyde.The rate and yield of this reaction strongly depended on the nature of substituents on the alcohol.For4‐nitrobenzyl alcohol,<10%of it was converted into the corresponding carboxylic acid after24h.By contrast,4‐methoxybenzyl alcohol and diphenylmethanol were completely converted into thecorresponding carboxylic acid and ketone after only9and3h,respectively.The conversion ratesfor oxidation of aromatic aldehydes by NGO carbocatalysts were higher than those for alcohol oxidation.For all the aldehydes,complete conversion to the corresponding carboxylic acids wasachieved using7%(mass fraction)of NGO at70°C within2–3h.Possible mechanisms for NGOcarbocatalyst structure‐dependent oxidation of benzyl alcohols and structure‐independent oxidationof aromatic aldehydes are discussed.