Hot compression test of a novel nickel-free white alloy Cu?12Mn?15Zn?1.5Al?0.3Ti?0.14B?0.1Ce (mass fraction, %) was conducted on a Gleeble?1500 machine in the temperature range of 600?800 °C and the strain rate range of 0.01?10 s?1. The constitutive equation and hot processing map of the alloy were built up according to its hot deformation behavior and hot working characteristics. The deformation activation energy of the alloy is 203.005 kJ/mol. An instability region appears in the hot deformation temperature of 600?700 °C and the strain rate range of 0.32?10 s?1 when the true strain of the alloy is up to 0.7. Under the optimal hot deformation condition of 800 °C and 10 s?1 the prepared specimen has good surface quality and interior structure. The designed nickel-free alloy has very similar white chromaticity with the traditional white copper alloy (Cu?15Ni?24Zn?1.5Pb), and the color difference between them is less than 1.5, which can hardly be distinguished by human eyes.
Microstructure and texture evolution of Cu-0.23%Al2O3 dispersion strengthened copper alloy, deformed at room temperature or cryogenic temperature, were investigated. The main textures in hot-extruded specimen were Brass {011} 〈211〉 and Cube {100} 〈100〉. Textures of Brass {011} 〈211〉 and Goss {011} 〈100〉 were observed in specimen after deformation at room temperature; while textures of Brass {011} 〈211〉, Goss {011} 〈100〉 and S {123} 〈634〉 were detected after deformation at cryogenic temperature. It is believed that the additional Al2O3 nanoparticles can result in dislocation pinning effect, which can further lead to the suppression of dislocations cross-slip. While in the specimen deformed at cryogenic temperature, both pinning effect and cryogenic temperature are responsible for the formation of Brass, Goss and S textures.
对应用于太阳能光热领域的TiO_2进行掺氮,并与不锈钢(stainless steel,SS)复合,采用磁控溅射法制备SS-TiON(HMVF,high metal volume fraction)/SS-TiON(LMVF,low metal volume fraction)串联双吸收层,并制备4层结构的太阳能光谱选择性吸收光热薄膜Cu/SS-TiON(HMVF)/SS-TiON(LMVF)/Al_2O_3。利用紫外–可见分光光度计、红外光谱仪、吸收率发射率测试仪、X射线光电子能谱仪与原子力显微镜等表征该太阳能光热吸收薄膜的光学性能、成分、结构与形貌。结果表明,通过优化双吸收层的厚度与成分,沉积在Al基底上的Cu/SS-TiON(HMVF)/SS-TiON(LMVF)/Al_2O_3太阳能选择性吸收薄膜,具有较高的吸收率(0.902)和较低的发射率(0.052)。该膜系经400℃高温条件下大气退火2 h后,由于出现晶粒团聚现象,光学性能有所下降。
