宋杰光
,
王瑞花
,
王秀琴
,
富伟
,
李养良
,
马明亮
,
李世斌
,
纪岗昌
材料热处理学报
利用粉末冶金方法制备氧化铝-铝金属陶瓷材料,研究其烧结工艺对其性能影响.结果表明,烧结温度从700℃逐渐升到1000℃且保温1h的条件下,Al2O3/Al金属陶瓷的显微结构致密化程度逐渐降低,硬度逐渐降低,电阻率逐渐升高.在显微结构中颗粒呈连续分布且较大的为金属Al,颗粒呈不连续分布较且细小的为Al2O3.在700℃温度下,随保温时间延长,其显微结构组织越致密,硬度越高,电阻率越低.在700℃烧结3h制备得到25 mass％ Al2O3/Al金属陶瓷,其显微结构致密化程度较高,硬度为2203 HV,电阻率为0.0159 Ω·m.
关键词:
金属陶瓷材料
,
烧结工艺
,
氧化铝
,
铝
MA Zhongyi
,
LU Yuxiong
,
BI JingInstitute of Metal Research
,
Chinese Academy of Sciences. Shenyang
,
ChinaZHANG YuzhengNortheastern University
,
Shenyang. China Manuscript received 16 May
,
1994
金属学报(英文版)
The tensile tests on the silicon carbide whisker and paniculate reinforced 2124A1 and 2024Al alloy composites fabricated by P/ M technique were carried out at the temperatures ranging from room temperature to - 196C . and the fracture surfaces were examined. The cryogenic strength of the composites increases with the decreasing test temperature. Clean interface is beneficial to the improvement in cryogenic strength of the composites. The effect of the interface characteristics on the paniculate composite is less than that on the whisker composite. With the decreasing temperature, the increase in strength of the whisker composite is more than that of the paniculate composite, which could be attributed to different strengthening mechanism.
关键词:
composite
,
null
,
null
,
null
S.B. Zhang and H. Nejishi (Department of Mechanical Engineering and Intelligent Systems
,
University of E feetro- Communications
,
Chofugaoka 1-5-1
,
Chofu-shi
,
Tokyo 182-8585
,
Japan)
金属学报(英文版)
In this paper local compressive deforming of a hexagonal tube of aluminum (JISA1050) is investigated by an electromagnetic forming. The hexagonal tubes are annealed for 1h. at 400℃, which have 55mm width with 1mm thickness, and 10mm corner edius. The deformed ation of the hexagonal tube, i.e., bead width, is 10, 15, 20mm, respectively. The magnetic flux density in the gap between the field shaper and the external surface of hexagonal tube is measured, and the result is that the magnetic flux density for a given voltage is almost identical along the gap) and decreases with increasing the gap. The profiles and the strain distribution of the hexagonal tube de- formed are affected by the change Of the charging voltage and the dimensions of a bead width. The greater compressive strum in the cireuwtrential direction is develOPed on plane part near corner,while tensile strain on the corner occurs. A metallic block is inserted inside the hexagonal tube so that uniform profile can be obtained. The simulation of the forming is performed by a finite-element method and compared with the experimental results.
关键词:
electromagnetic forming
,
null
,
null
,
null
,
null
宋杰光
,
王瑞花
,
王秀琴
,
王芳
,
李世斌
,
纪岗昌
材料热处理学报
利用粉末冶金方法制备氧化铝-铝金属陶瓷材料,研究其致密化机理.结果表明,当成型压力为20 MPa时,样品表面比较平整,凹坑很少,致密化程度较高.当烧结温度为800℃时,颗粒间的结合强度比较高,样品很致密,但是在样品面上有铝析出,形成特殊的球状堆积物.75％ Al样品中组织最为致密.通过优化处理,可以获得外形规整、致密度高且氧化铝弥散均匀的氧化铝-铝金属陶瓷材料,其致密度为95.62％.
关键词:
金属陶瓷材料
,
致密化机理
,
氧化铝
,
铝
郭亚杰
,
徐顺建
,
刘桂武
,
乔冠军
机械工程材料
制备了一种新型铝颗粒弥散分布的纳米孔碳基复合材料,并以此作为对电极的催化层,研究了催化层厚度对该对电极染料敏化太阳能电池(DSC)光电性能的影响以及铝颗粒的作用机制.结果表明:随催化层厚度的增大,纳米孔碳基复合材料对电极DSC的转换效率先增后减,在催化层厚度为44μm时达到最大,为5.15％,比纯碳对电极DSC的增加21.5％;细小铝颗粒弥散分布于复合材料对电极中,起连接碳颗粒的桥梁作用,能够加快外电路电子传输,从而加速电解质还原,使催化层增厚提高催化活性的作用得以充分发挥,并抵消催化层增厚导致的方块电阻的升高效应,最终提升了DSC的转换效率.
关键词:
纳米孔碳
,
对电极
,
转换效率
,
铝
,
染料敏化太阳能电池
