PLA/人造岗石废渣复合材料的制备及其性能

采用熔融共混法制备了聚乳酸/人造岗石废渣(PLA/AMWs)复合材料,研究了AMWs含量对PLA/AMWs复合材料结晶速率、热变形温度和力学特性等的影响。结果表明,AMWs能够显著提升PLA的结晶速率和力学性能,加入约40%AMWs的PLA/AMWs复合材料,半结晶时间缩短了61%(10℃/min降温)。另外,加入约20%AMWs时,弯曲强度和冲击强度较纯PLA分别增长285%和146%。本文研究实现增值化应用AMWs,降低PLA应用成本和改善PLA韧性较低的缺陷,助力可生物降解塑料的应用。

Thermodynamics Behavior of Titanium for BOF Smelting Bearing Steel

When titanium element appears in bearing steel, it is very easy to create titanium nitride inclusion, which reduces the fatigue life of bearing steel. Based on the production data of bearing steel produced by BOF, it is found that the titanium takes its source in bearing steel; the factors-affecting titanium content, and the thermodynamics behavior of titanium under smelting condition were studied. The results show that the prime reasons of titanium content increment are the soluble aluminum content and the titanium oxide of slag. The comparison between the experimental data and theoretical ones shows that there is a big declination when the soluble aluminum content of steel is higher, which is caused by the nonequilibrium reaction of slag and steel. The apparent equilibrium distribution coefficient of titanium between slag and steel is Obtained by use of experimental data.

汽车用固定螺栓断裂原因分析

针对某汽车公司在现场装配校验拧紧时发生的断裂问题,使用金相显微镜、扫描电镜、能谱仪等进行分析。结果表明:从断裂螺栓陈旧断口的宏观、微观形貌以及能谱元素分析结果确定螺栓断裂发生在表面处理之前,为淬火裂纹,裂纹源于螺纹牙根处,并从轴向扩展开始,转为横向,最终在校验拧紧时发生一次性断裂。