等径角挤压铜合金的分节断裂（英文）

本研究提供了等径角挤压不同铜合金的局部剪切、坯锭开裂和分节断裂的实验依据。结果表明,尽管很多参数影响局部剪切,但是合金的硬度和分节断裂与其有着直接的关系,而硬度与合金的成分和相组成有关。在室温下,α-黄铜可以成功进行等径角挤压,而α/β黄铜甚至在350℃下都不能成功进行等径角挤压。利用DEFORM^(TM)软件模拟了开裂和分节断裂,研究不同参数对分节断裂的影响。结果表明,摩擦力和加工速率对获得完美坯锭影响很小,而利用背压可以很好地减小局部剪切、坯锭裂纹、分节断裂和破坏。利用背压能减小流动局部化,当背压由0提高到600Mpa时,可以提高材料流动均匀性并且使坯锭的均匀性提高36.1%。

Investigation of the Impact of Calcinations Temperature on the Prop-erties of Ba Doped HfO2 Nano-rods

Barium doped hafnium oxide nanoparticles were synthesized by an easy co-precipitation method. FTIR analysis and EDX investigation shows the purity and stoichiometric composition of hafnium oxide nanoparticles. XRD investigation exhibit the as syn-thesized nanoparticles are amorphous in nature and calcined barium doped hafnium oxide nanoparticles have the monoclinic phase structure with the mean crystallite size was around 15 nm. TEM analysis shows the development of crystalline Nano-rods. The Na-no-rod formations signify the possibility of its use in applications of sensor. Ultra violet visible spectroscopy investigation shows that the band gap of the nanoparticles is noticed between 5.4-5.14 eV. The visible and NIR of barium doped hafiniura oxide nanoparticles indicated high reflectance, which may possibly be employ as an antireflection coating in solar cells applications and high absorbance ultra violet region signify the viability of make use of the prepared nanoparticles could be used in Opto-electronic device applica-tions.