M.Krauss
,
B.Scholtes
材料科学技术（英文）
The lifetime of hot-work tools is often limited by the development of thermal shock cracks. To analyze the influence of near-surface materials states on the damage process during thermal shock loading, isothermal annealing experiments and thermal shock tests with hot-work tool steel AISI H11 in hard turned, electroeroded, shot-peened or deep rolled surface conditions were performed. Cyclic thermal shock tests were carried out by heating and subsequent quenching of specimens. Crack depths and crack densities were investigated after 100, 1000, 10000 and 30000 cycles at microsections using optical microscopy. Complementary, residual stresses were determined by X-ray diffraction-(XRD) stress analysis. Under identical thermal loading conditions characteristic cracking behaviour was observed at different surface types examined. Neither deep rolling nor shot-peening results in decreasing crack lengths compared to hard turned surface conditions. While the residual stress state during simple annealing is proportionally stable, almost all initial residual stresses relaxed during a few hundred thermal shock cycles. Additional Martens-hardness measurements and FWHM values of XRD analyses indicate that the work hardening induced by mechanical surface treatment is not stable under thermal shock loading.
关键词:
Thermal shock
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null
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null
张静静
,
高鸿
,
刘泊天
,
邢焰
,
李博弘
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2015.01.009
为考察在轨温度环境对J-47C结构胶黏剂粘接性能的影响,利用动态热机械分析和热重分析方法,对其Tg、热分解温度进行了测试,掌握了胶黏剂的耐热指标.通过不同温度下力学性能测试,温度冲击及真空热循环试验研究了卫星特殊的温度环境对胶黏剂性能的影响.结果表明,J-47C胶黏剂在高温以及真空热循环和温度冲击后其仍具有较高的力学强度保持率,满足卫星的温度环境对胶黏剂性能的需求.
关键词:
胶黏剂
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空间环境
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温度冲击
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真空热循环
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粘接性能
