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Effect of Al content on high temperature erosion properties of arc-sprayed FeMnCrAl/Cr_3C_2 coatings
Three types of FeMnCrAl/Cr3C2 coatings with different Al content were deposited on 20# steel substrates by the high velocity arc spraying (HVAS) process. Surface microstructures of the coatings were analyzed by optical microscopy (OM) and X-ray diffractometry (XRD). High temperature erosion (HTE) tests were performed in an erosion tester at different impact angles. The surface morphologies of the eroded coatings were observed on a field emission scanning electron microscope(FE-SEM). The laminated structure is found on all the prepared coatings with the porosity and oxide fraction in the coatings decreasing with the Al content from 0 to 15% (mass fraction). Sample FA3 with 15% Al, possessing the lowest porosity and oxide fraction, has the best HTE resistance, which demonstrates that Al addition can improve the HTE resistance of the coatings. The erosion rate of sample FA1 exhibits a maximum value at 90° impact angle. The maximum erosion rates of both FA2 and FA3 samples appear in the range of 60°-90° impact angles. Erosion loss of the coatings occurs through brittle breaking, cutting and fatigue spalling. 相似文献
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本文研究了采用低温化学镀制备的新型超细Al2O3-TiC-8%Co(ATC)金属陶瓷的干滑动磨损性能.在销盘式磨损机上考察了新型金属陶瓷材料分别与45#淬火钢和SiC配副磨损实验中的磨损失重.采用SEM对新型金属陶瓷材料进行元素分布分析、断口形貌分析和磨损面形貌分析.发现干滑动摩擦条件下,新型金属陶瓷材料因其较高的断裂韧性和硬度而具有优良的耐磨性能.在磨损过程中以磨粒磨损为主,随摩擦时间延长表面微细突起脱落,磨损面趋于平滑,磨损量减少.金属钴均匀分散在整个陶瓷基体中,形成三维网状结构,在负载条件下可产生一定程度的塑性变形,吸收部分能量.因此,独特的金属钴的复合方式不仅抑制烧结过程中晶粒长大、增大新型金属陶瓷材料的断裂韧性,还提高其耐磨性能. 相似文献
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采用超声波辅助化学镀法在室温条件下制备了Co/Al2O3复合粉体,1200℃下热处理1.5h获得了CoAl2O4尖晶石粉体。用扫描电镜、透射电镜和X射线衍射测定了粉体的微观形貌、成分和相组成;用差热分析法确定了粉体的尖晶石转变温度。结果表明:镀覆制备的Co/Al2O3复合粉体由金属钴和Al2O3两相组成,金属钴相包覆Al2O3相,Co包覆层在Al2O3颗粒表面分布均匀且结构较疏松;复合粉体的尖晶石转变温度为850℃左右;转变后获得的粉体也是一种复合粉体,由Al2O3和CoAl2O4两相组成,由粉体的生长机制可预见,它是以α-Al2O3为核心CoAl2O4尖晶石包覆在其表面的结构。 相似文献
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饮用水系统黄铜零件表面脱铅的研究 总被引:4,自引:0,他引:4
研究试制了一种用于黄铜管道,水龙头和管接头等饮用水系统用零件的表面脱铅的脱铅试剂,利用X射线能谱测定了经表面化学处理后的黄铜零件表面的含铅量,并用吸收光谱分析了脱铅处理后脱铅溶液中的Pb/Cu和Pb/Zn的量。 相似文献