镁合金表面TaC/TaC-Mg/Mg梯度涂层的 残余热应力分析

采用间歇式挤出发泡工艺制备淀粉/PVA复合发泡材料。在淀粉含量固定、甘油作为增塑剂的情况下，研究偶氮二甲酰胺（AC发泡剂）与聚乙烯醇（PVA）的含量对发泡材料的表观密度、发泡倍率、相对硬度、吸水性能、回弹性能以及压缩性能等的影响。结果表明：随着PVA含量的升高，复合材料的表观密度和压缩模量减小，回弹性能变好。PVA含量对吸水率影响不明显，吸水率稳定在20%左右。吸水至饱和状态后，相对硬度随着PVA含量的增加而不断增加。随AC发泡剂含量的升高，复合材料的表观密度减小，相对硬度降低，发泡倍率和回弹率增加，材料的泡孔孔径逐渐增大但是发泡孔径的均匀性变差。当PVA、AC发泡剂的添加质量分数分别为30%, 1%时，复合材料性能最优。

Analysis of Thermal Residual Stresses of TaC/TaC-Mg/Mg Gradient Coating on Magnesium Alloy

Starch /PVA composite foaming materials were prepared by the batch extrusion foaming processing. With fixed starch content and glycerol as plasticizer, the influences of the dosage of Azodicarbonamide (AC foaming agent) and Polyvinyl Alcohol (PVA) were studied on the apparent density, foaming ratio, relative hardness, water absorption rate, springback property and compression property of the foamed materials. The results indicated that with the increase in the content of PVA, the apparent density and the compression modulus of the composite foam material decreased, while the springback property of the material became better. The effect of PVA content on water absorption was not obvious, and the water absorption was stable at about 20%. When absorbing water to a stable state, the relative hardness increased with the increase of PVA content. With the increase in the content of AC foaming agent, the apparent density and relative hardness of the composite material decreased, the foaming ratio and the rebound rate increased, and the cell diameter gradually increased while the uniformity of cell diameter decreased. When the PVA content was 30% and the content of foaming agent was 1%, the material performance was the best.