【摘 要】
:
The extrusion of Al-Si alloy powders with different particle sizes allows manufacture of different products with unique microstructures and therefore with uniqu
【机 构】
:
School of Materials Science and Engineering,Department of Mechanical and Electronic Engineering
论文部分内容阅读
The extrusion of Al-Si alloy powders with different particle sizes allows manufacture of different products with unique microstructures and therefore with unique mechanical properties. The effects of powder size on the extrusion behavior and process defect of Al-18% Si alloy were studied by means of microscopy (optical, scanning electron) and density determination. The main objective of the work is to demonstrate the influence of the powder material characteristics on final density and quality of bar. The results show that the bigger the powder particles, the better the performance of cold compacting. The surface of alloy bar extruded from big particles has good quality without cracking. While the smaller the powder particles, the higher the density and the better the microstructure and mechanical properties. For practice application, the mixed powders are better than single powder.
其他文献
博Ⅲ优9678是博白县农业科学研究所用自育的优质不育系博ⅢA与R9678配组育成的弱感光型杂交水稻新组合,在桂南稻作区感光组区试和不同区域示范试验中,表现出株型适中、产量较
目的 探讨人眼巩膜组织细胞外基质中Ⅰ型胶原纤维蛋白表达量的变化与病理性近视的相关性.方法 收集病理性近视合并开角型青光眼组15眼、开角型青光眼组15眼及正常眼15眼的巩
为比较S.sclerotiorum侵染后,油菜不同抗性品种组织内活性氧产生情况,通过DAB和伊文思兰染色,分别检测接种病菌后不同抗感品种的氧迸发(Reactive Oxygen Intermediates,ROIs)
为摸清沂蒙山区石质褐土经济林树盘覆盖处理对水土保持效果和土壤理化性状的影响,进行了石榴园树盘土壤覆草、盖膜和松土试验。结果表明,所有处理的蓄水增温保肥效果及对土壤
研究了西北旱寒区大田条件下不同种植密度对冬油菜越冬率、产量及其构成因素、结角层结构、含油率等的影响。结果表明,群体密度在120万株/hm2~60万株/hm2,越冬率可达到80%以
甜菜碱(Betaine)作为甲基供体参与了体内蛋氨酸的循环,提高动物生产性能其作用主要通过节约部分Met实现.此外,甜菜碱也可通过影响动物体内激素水平而提高动物的生长性能.
基于最大似然序列估计准则,提出了3种先验信息辅助的8PSK调制信号的信噪比估计方法.与现有硬判决辅助的信噪比估计方法进行了比较,解决了现有方法在低信噪比时估计误差较大的
采用嵌入式归航控制器、双天线GPS定位定向仪、无线数传机、大力矩直流伺服电机等设备,自主设计归航控制、落点预置、遥控通讯和GPS数据处理等软件,研制具有自动归航和人工遥
A 3-D simulation of grain growth was conducted by utilizing cellular automata (CA) and Monte Carlo (MC) algorithm. In the simulating procedure, the three-dimens
采用第一原理方法,基于ultrasoft赝势、密度函数理论,从原子层面对纯γ Mn的顺磁、铁磁和反铁磁性状态下的电子、基态属性、相稳定和磁有序结构进行了研究.通过自旋极化分析