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The electronic packaging shell with high silicon carbide aluminum-base composites was prepared by semi-solid thixoforming technique. The flow characteristic of the Si C particulate was analyzed. The microstructures of different parts of the shell were observed by scanning electron microscopy and optical microscopy, and the thermophysical and mechanical properties of the shell were tested. The results show that there exists the segregation phenomenon between the Si C particulate and the liquid phase during thixoforming, the liquid phase flows from the shell, and the Si C particles accumulate at the bottom of the shell. The volume fraction of Si C decreases gradually from the bottom to the walls. Accordingly, the thermal conductivities of bottom center and walls are 178 and 164 W·m-1·K-1, the coefficients of thermal expansion(CTE) are 8.2×10-6 and 12.6×10-6 K-1, respectively. The flexural strength decreases slightly from 437 to 347 MPa. The microstructures and properties of the shell show gradient distribution. 相似文献
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研究了添加青铜粉对316L烧结不锈钢的密度、硬度和微观组织的影响。结果表明:添加青铜粉末提高了316L不锈钢的生坯密度。烧结样品的密度和硬度均随青铜粉体积分数的增大而提高,烧结温度升高也有利于316L烧结不锈钢密度和硬度的增大,最佳烧结温度为1200℃左右。当青铜粉的体积分数为30%、烧结温度为1200℃时,316不锈钢的最大相对密度和硬度分别为95.1%和HRB83。添加青铜粉引起的液相烧结使不锈钢颗粒球形化趋势明显,颗粒表面平直化。 相似文献
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粉末冶金高速压制成形的压制方程 总被引:7,自引:0,他引:7
瑞典Hydropulsor AB制造并出售其独创的液压冲击机后,解决了长期以来限制高速压制技术工业化应用的设备问题,使该技术得到极大的推动。文内介绍了高速压制的特点,如压制压力、压制速度、压坯密度分布,脱模压力等;对高速压制致密化机制进行了探讨,提出了“热软化剪切致密化机制”,据此给出了相应的压制方程Inφ=k1△HL/k2 exp[kz(1-P/△HL)+C。并利用实验数据进行了验证。结果表明,该方程具有满意的精度和广泛的适用性。 相似文献
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粉末法制备太阳能电池Cu2ZSnS4薄膜吸收层 总被引:3,自引:0,他引:3
使用感应熔炼法制备Cu-Zn-Sn合金,并利用单辊甩带制备连续均匀的Cu-Zn-Sn合金薄带.球磨Cu-Zn-Sn合金薄带后和硫粉混合制成粉末前驱体,再将粉末前驱体涂敷在钠钙玻璃基体上在H2 S(g)和N2 S(g)气氛中退火,得到太阳能电池薄膜吸收层用材Cu2ZnSnS4.利用X.射线衍射仪(XRD)、扫描电镜(SEM)和能谱仪(EDS)对Cu-Zn-Sn合金薄带及Cu2ZnSnS4薄膜进行分析和表征,并利用可见光.紫外分光光度计测量Cu2ZnSnS4薄膜的吸收率和透光率.结果表明:使用单辊甩带法可以制备出成分均匀的脆性合金薄带,薄带厚度为6~10 μm.在N2 S(g)气氛下400℃退火后可制成比较纯净的具有锌黄锡矿结构的Cu2ZnSnS4薄膜,其禁带宽度为1.61 eV. 相似文献
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