一种高性能的新结构IGBT

提出了一种低功率损耗的新结构IGBT.该新结构的创新点在于其复合耐压层结构,该耐压层包括深扩散形成的n型缓冲层和硼注入形成的透明背发射区两部分.虽然在正常工作条件下,该新结构IGBT工作于穿通状态,但器件仍具有非穿通IGBT(NPT-IGBT)的优良特性.该新结构IGBT具有比NPT-IGBT更薄的芯片厚度,从而可以获得更好的通态压降和关断功耗之间的折衷.实验结果表明:与NPT-IGBT相比较,新结构IGBT的功率损耗降低了40%.     

热作模具钢表面激光堆焊耐磨合金层的研究

本文主要通过在H13钢上用大功率CO_2激光束进行堆焊,阐述了激光堆焊工艺变化对堆焊组织和性能的影响,在本试验条件下,得到了高密度弥散金属化合物组织的激光堆焊层,平均硬度为HV800,与基体呈冶金结合,耐磨性比H13模具钢提高149%。     

新世纪我国压铸业与国际接轨的思考

针对中国压铸行业的现状和存在的问题 ,以及当前的机遇和面临的挑战 ,论述了中国压铸工业进入 2 1世纪所面临的新形势及应采取的对策     

浅谈冲压模具的维修要领及常见故障的排除

介绍冲压模具修理和检查各环节的主要工作内容及维修要领 ,列举了常见故障的排除方法 ,通过总结实际生产中的修模经验 ,对缩短修模周期 ,降低成本 ,延长模具寿命有一定的参考价值。。     

超大型材生产经验

对几种超大型材挤压生产的工艺技术、工模具设计、挤压参数控制等过程进行了分析，通过例子总结了挤压生产超大型材的经验及关键技术。     

邻苯二甲酸酯鼓泡生物降解

该课题测试了邻苯二甲酸酯类化合物的鼓泡生物降解行为。结果表明，邻苯二甲酸酯的降解速率常数（kb)与其烷基链长度之间存在良好的相关性，kb=0.0009x^2-0.019x 0.1123，相关系数r=0.9906；浓度超过500mg/L时，邻苯二甲酸二乙酯可抑制自身的生物降解；中间产物邻苯二甲酸浓度超过50mg/L时，也对邻苯二甲酸二乙酯的生物降解有明显的抑制作用。     

Effects of solidification structure on fatigue crack initiation and fatigue strength in Al−Si−Mg cast alloys

Rotating-bending uniaxial fatigue tests and micro-fatigue crack initiation tests were carried out using a permanent mold cast (PMC) and semi-solid die cast (SDC) with Al−7%Si−0.35%Mg composition in order to examine the relationship between solidification structures and fatigue behaviors. The crack length was measured using a replication method. Fatigue strength was improved in SDC, which was almost consistent with the predicted fatigue strength using the size of Si particle cluster. Resistance to fatigue crack initiation and fatigue strength were improved in SDC owing to the finer Si cluster and to higher ultimate tensile strength. Fatigue crack in PMC was preferentially initiated at pores. For SDC, the fatigue crack was initiated at the Si particle/matrix interface, and then sucessively grew along eutectic cell boundaries.     

Failure analysis of a hot extrusion die used for Al-Li alloy processing

Al-Li alloys being developed as lighter, substitutes for conventional high strength Al alloys are to be processed by routine methods. During extrusion of a 8090 Al-Li alloy, the extrusion die container failed causing some alarm. This failed die container was analysed to examine if the failure was caused by interaction of Li diffusing out of Al-Li alloy with the carbides of die steel. The evidence, although not conclusive, is sufficient to exercise caution during such processing.     

针刺合成革基布质量的探讨

分析了针刺合成革基布质量的控制要素 ,以及预针刺机的牵伸比和针刺机的步进图对基布质量的影响