排序方式: 共有58条查询结果,搜索用时 31 毫秒
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35CrMo钢复合型裂纹的疲劳门槛值 总被引:1,自引:1,他引:0
研究了35CrMo钢试样在860℃淬火+不同温度回火态的复合型裂纹疲劳门槛值。采用对称四点弯曲测定Ⅰ型、反对称四点弯曲测定Ⅰ+Ⅱ型、斜裂纹对称四点弯曲测定Ⅰ+Ⅲ型裂纹的疲劳门槛值。试验结果表明:35CrMo钢各种回火组织的Ⅰ+Ⅱ和Ⅰ+Ⅲ型疲劳门槛值均低于相应的Ⅰ型疲劳门槛值。Ⅰ型尖裂纹的疲劳门槛值比钝裂纹的低,但Ⅰ+Ⅲ复合型尖裂纹的疲劳门槛值比钝裂纹的高。35CrMo钢疲劳门槛值随回火温度升高出现峰值。Ⅰ型和Ⅰ+Ⅲ型在400℃回火态最高,Ⅰ+Ⅱ型在550℃回火态最高。疲劳门槛值既受强度制约也与塑性有关.对应强度升高的速率与塑性变形两个因素配合适宜时出现峰值。 相似文献
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Microstructure and properties of TiN/Ni composite coating prepared by plasma transferred arc scanning process 总被引:1,自引:0,他引:1
The TiN/Ni composite coatings were deposited on 7005 aluminium alloy by high speed jet electroplating and then processed with plasma transferred arc(PTA) scanning process. The microstructure, microhardness and friction coefficient of PTA scanning treated specimens were investigated. It is shown that the PTA scanning treated specimens have a rapidly solidified microstructure consisting of the uniformly distributed TiN phase and fine Al3Ni2 intermetallic phases. The composite coating has an average microhardness of approximately HV 800. The friction coefficient of PTA scanning treated specimens (oscillated at around 0.25) is considerably lower than that of TiN/Ni composite coating (oscillated at around 0.35). The corrosion behavior of the composite coating in 3.5% NaCl solution at room temperature was also determined using a potentiostat system. In comparison with the corrosion potential corr of −0.753 V for 7005 aluminium alloy, the corrosion potentials for TiN/Ti composite coating and PTA scanning treated specimen are increased by 0.148 V and 0.305 V, respectively. The PTA scanning treated specimen has the lowest corrosion current densityJcorr as well as the highest corrosion potential corr, showing an improved corrosion resistance compared with 7005 aluminium alloy. 相似文献
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超音速火焰喷涂涂层耐磨性能研究进展 总被引:1,自引:0,他引:1
从超音速火焰喷涂工艺特点和涂层耐磨性能,综述了超音速火焰喷涂耐磨涂层研究进展.指出超音速火焰喷涂技术在航空航天、石油机械、液压传动、燃气涡轮机轴类零部件制造和修复中的应用,并展望了超音速火焰喷涂的发展方向. 相似文献
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高铬铸铁在进口抛丸机叶片上的应用 总被引:1,自引:0,他引:1
一、引宫高铬白日铸铁自七十年代中期开始研究以来,以其良好的耐磨性和较高的韧性在水泥、电力、矿山和轧钢机械中得到广泛的应用。目前国内部分抛丸机叶片也已开始使用高铬铸铁。但还有一些国外进口抛丸机使用国产叶片仍存在使用寿命低,周期短,成本高等问题,为使国产叶片的耐磨性得到提高,以代替进口叶片,故开展提高高铬铸铁叶片耐磨性的研究。二、叶片材质的成分和铸造工艺高铬铸铁中的铬是碳化物的主要形成元素,当铬含量大于12%时,将形成硬度为1300-188Hv的外CS型碳化物肝],比低铬铸铁中吗C碳化物840-llopHV硬度高,并且… 相似文献
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