Cooling rate effects on the structure and transformation behavior of Cu-Zn-Al shape memory alloys

来源 :International Journal of Minerals Metallurgy and Materials | 被引量 : 0次 | 上传用户:lcc54202346
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Different fragments of a hot-rolled and homogenized Cu–Zn–Al shape memory alloy(SMA) were subjected to thermal cycling by means of a differential scanning calorimetric(DSC) device. During thermal cycling, heating was performed at the same constant rate of increasing temperature while cooling was carried out at different rates of decreasing temperature. For each cooling rate, the temperature decreased in the same thermal interval. During each cooling stage, an exothermic peak(maximum) was observed on the DSC thermogram. This peak was associated with forward martensitic transformation. The DSC thermograms were analyzed with PROTEUS software: the critical martensitic transformation start(Ms) and finish(Mf) temperatures were determined by means of integral and tangent methods, and the dissipated heat was evaluated by the area between the corresponding maximum plot and a sigmoid baseline. The effects of the increase in cooling rate, assessed from a calorimetric viewpoint, consisted in the augmentation of the exothermic peak and the delay of direct martensitic transformation. The latter had the tendency to move to lower critical transformation temperatures. The martensite plates changed in morphology by becoming more oriented and by an augmenting in surface relief, which corresponded with the increase in cooling rate as observed by scanning electron microscopy(SEM) and atomic force microscopy(AFM). Different fragments of a hot-rolled and homogenized Cu-Zn-Al shape memory alloy (SMA) were subjected to thermal cycling by means of a differential scanning calorimetric (DSC) device. increasing temperature while cooling was carried out at different rates of decreasing temperature. in each cooling stage, the temperature decreased in the same thermal interval. with forward martensitic transformation. The DSC thermograms were analyzed with PROTEUS software: the critical martensitic transformation start (Ms) and finish (Mf) temperatures were determined by means of integral and tangent methods, and the dissipated heat was evaluated by the area between the corresponding The effects of the increase in cooling rate, assessed from a calorimetric viewpoint, consisted in t The augment of the exothermic peak and the delay of direct martensitic transformation. The latter had the tendency to move to lower critical transformation temperatures. The latter had the tendency to move to lower critical transformation temperatures. in cooling rate as observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM).
其他文献
欧债危机正在持续发展,本文回顾了欧债危机爆发的过程,分析了欧债危机对欧盟经济的影响。 The debt crisis in Europe is continuing to develop. This article reviews the
The effect of cooling rate on the crystallization of perovskite in high Ti-bearing blast furnace (BF) slag was studied using confocal scanning laser microscopy
The ethanolic extract ofKleinia grandifloraleaves was characterized and tested for its potential anticorrosion properties on mild steel in 1 M H2SO4 medium usin
本文分析了我国环境监测分析方法的现状和存在问题,提出了改进和完善我国环境监测分析方法的对策建议。
Ceramic materials were investigated as thermal barrier coatings and electrolytes. Electrophoretic deposition (EPD) and physical vapor deposition (PVD) were empl
自从21世纪90年代以来,经济全球化得以迅速地发展,其中,主要体现在金融、市场贸易和生产的全球化。中国经济在经济全球化影响下面临发展机遇的过程中,挑战也是不可避免的。在
在经济发展过程中,贵州省城乡居民收入差距持续拉大。虽然近年来贵州省不断从政策、制度、财政等各方面加大对于农村地区的扶持力度,但贵州省城乡居民收入仍然高达4.1:1。二
We performed fluidized bed coating of Al-based nanocomposite powder–binder suspensions onto polymer substrates. The effects of the type and amount of the binde
On the basis of the practical production of non-oriented silicon steel, the formation of Mg O·Al2O3 inclusions was analyzed in the process of “basic oxygen fu
我国十二五科技发展规划加速推进城镇化建设,城镇化是实现农村现代化的必然选择,长期以来,我国城镇化过度追求经济发展,忽略了生态环境问题,生态环境恶化严重影响城镇化进程,