A.Abdollah-zadeh
,
M.S.Jamshidi
,
S.M.M.Hadavi
材料科学技术（英文）
Thermal fatigue behavior of hard chromium electroplated steel in three different crack intensities of high contraction (HC), medium contraction (MC) and low contraction (LC) was studied. Maximum and minimum temperatures during thermal cycle were 800 and 100℃, respectively. The topography and cross sections of the samples exposed to 50, 100 and 200 thermal cycles were studied. The thermal fatigue behavior was analyzed using the data obtained from surface roughness, crack networks and stress induced during cycles. Although the as-coated sample with LC chromium contained no crack, it appeared to have a high crack density after only 50 cycles. The crack depth and width in cyclically oxidized LC coating were much less than those in MC and HC coatings. It was concluded that the LC coating protected the substrate from having cracks or subsurface oxidation during thermal fatigue. The cracks in the HC and MC coatings increased in density as well as in depth by thermal cycles. Moreover, the opening of the cracks to the substrate resulted in sub-surface oxidation.
关键词:
Thermal fatigue
,
null
,
null
Bin ZHANG
,
Qingyuan YU
,
Jun TAN
,
Guangping ZHANG
材料科学技术（英文）
200-nm-thick Au interconnects on a quartz substrate were tested in-situ inside a dual-beam microscope by applying direct current, alternating current and alternating current with a small direct current component. The failure behavior of the Au interconnects under three kinds of electric currents were characterized in-situ by scanning electron microscopy. It is found that the formation of voids and subsequent growth perpendicular to the interconnect direction is the fatal failure mode for all the Au interconnects under three kinds of electric currents. The failure mechanism of the ultrathin metal lines induced by the electric currents was analyzed.
关键词:
Au interconnect
,
null
,
null
,
null
王海棠
,
李元东
,
杨贵荣
,
刘生龙
,
郝远
表面技术
doi:10.3969/j.issn.1001-3660.2009.06.012
为了满足工况条件对表面功能材料在高温、摩擦和激冷激热等方面的要求,采用负压铸渗法在铸铁表面制备了Ni/WC复合渗层,观察了渗层与基体结合形貌,研究了渗层的热疲劳性能.结果表明:在热循环过程中,渗层与基体表面出现了不同程度的氧化现象,裂纹开始出现的热循环次数随着渗层中WC含量的增加而增加,表面复合渗层最终剥落破损的热循环次数随着WC含量的增加呈先增加后减少的趋势.
关键词:
渗层
,
热疲劳
,
热应力
