简介:ExperimentswerecarriedouttostudytheinfluenceofsurfaceconditiononexpulsionduringthespotweldingofAZ31BMgalloy.AgeneralelectricalcontactresistancetheoryforconductiveroughsurfacesandtherelationbetweenmaximumtemperatureTminthecontactandvoltage-dropVacrossinterfaceoftwosurfaceswereemployedtounderstandthereasonofexpulsioninMgalloyspotwelding.Themainreasonofexpulsionisthatthehighelectricalcontactresistanceinducedbylargeroughnessofthesurfaceandoxidefilmcoveredonthesurfaceleadstolocalmeltingofmetalintheinterfaceoftwosurfaces,andliquidmetalofthelocalareaejectedfromthespecimenunderelectrodeforceformsexpulsion.
简介:烟抑制机制和沥青的表演上的扩展石墨的效果被适用学习红外线的光谱学(英尺红外),X光检查衍射(XRD),扫描电子显微镜学(SEM)和全面热分析(TG,DSC)。试验性的结果证实与可扩充的石墨被混合的沥青将在热混合,和扩展石墨层的过程膨胀将在沥青由轻部件胀大。在沥青的轻部件并且哼扩展石墨表面或在在盘子之间的扩展石墨层的塞子的部分上的吸附使成核结晶化成为了生长。并且货车derWaals力量并且有效地格子罐头结合制止沥青烟版本。同时,有氧化罐头的膨胀代理人传播了进沥青,导致沥青氧化并且塑料减退,当韧性减少时。扩展石墨,SBS修饰词和环境友好的可塑剂习惯于合成修改沥青。根据沥青烟版本实验,沥青性能的正常测试,Brookfield粘性测试,RTFOT测试和沥青,混合测试(高温度稳定性,低温度稳定性,水稳定性),比到SBS的矩阵沥青和等价物的修改沥青的,修改沥青表演才好。而且,它有好烟抑制效果。
简介:CellularspacingselectionofCu-27.3wtpctMnalloyhasbeeninvestigatedbylasersurfacerapidresolidificationexperiments.Theexperimentalresultsshowthatthereexistsawidedistributionrangeincellularspacingunderultra-hightemperaturegradientandrapidsolidificationconditionsandtheaveragespacingdecreasewithincreaseofthegrowthrate.TheexperimentalresultsarecomparedwiththecurrentKGTmodelforrapidcellular/dendriticgrowth,andareasonableagreementisfound.