Liping LIANG
,
Shue DANG
,
Dong WU
,
Yuhan SUN
材料科学技术（英文）
Coprecipitation supercritical fluid drying technology has been employed to synthesize calcia-stabilized zirconia ultrafine powder with low-cost inorganic salts as the starting materials. The sintering behaviors of these powders were also investigated. The results showed that supercritical fluid drying could effectively alleviate the hard agglomeration of grains during the gel drying process, and the morphology of the powder retained the network texture of the original gel. The resulting particles were characterized by small particle size (5~20 nm), better monodispersity and high surface area, which gave rise to high activity and sinterability. Consequently, these powders could readily be compacted into the desired shape and their densification could be carried out in shorter time and at lower temperatures. For instance, nanometer-sized powder calcined at 600ºC for 2 h could be cold-pressed into a green body and sintered at 1100º for 0.5 h to attain a dense body with bulk density of 5.9718 g/cm3 and specific pore volume of 0.0008 cm3/g.
关键词:
Calcia-stabilized zircornia
,
null
,
null
,
null
闫志峰
,
贺秀丽
,
王文先
,
张红霞
稀有金属材料与工程
通过有限元软件模拟横向十字接头的实际焊接过程,并进行温度场和应力场分析,采用基于Dang Van准则考虑焊接残余应力的临界面法对AZ31B镁合金典型角接头型式——横向十字接头进行了疲劳评定研究,并与疲劳试验结果进行对比分析.结果表明,法国焊接研究所提出的钢材参数及国内研究者提出的铝合金材料的参数均不适用于AZ31B镁合金横向十字接头,需要进行修正;经试验研究将参数修正为α*=0.5,β*=55 MPa,并拟合出相应的Dang Van图形,其结果与疲劳试验结果相吻合;说明修正后的临界面法可以对AZ31B镁合金横向十字接头进行合理的疲劳评定,而且依据应力集中大小,可以有效预测试件可能的疲劳断裂位置.
关键词:
AZ31B镁合金
,
横向十字接头
,
疲劳评定
,
临界面法
