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The porous superalloy materials with hollow spherical pores were fabricated by using metal powder sintering process. The scanning electron microscope (SEM) observation was applied to the test samples and it revealed that the pores of the porous material exhibited a uniform distribution and the apertures were of same size in principle. The sintering necks appeared between adjacent particles on metal skeleton after sintering. The mechanical properties of the test samples were analyzed and the result showed that this kind of materials possessed excellent energy absorption capability, and the compression resistance decreased with increasing the porosity and aperture. 相似文献
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用粉末烧结法制备了孔结构为球形中空孔和线型中空孔的镍基多孔高温合金材料.对试样进行显微组织观察和力学性能测试.结果表明:制备的多孔高温合金材料的孔隙分布均匀,孔径大小一致.通过高温烧结,多孔合金骨架处的金属颗粒之间形成了烧结颈,发生了烧结结合.生成孔的孔隙度随造孔剂(尿素)的添加量增加而增加,当造孔剂的质量分数为40%时,可得到孔隙度为81.62%的球形多孔材料.多孔材料具有优良的能量吸收性能,其压缩性能随孔隙度和孔径的增加而下降. 相似文献
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采用激光熔化沉积方法制备出Rene95镍基高温合金薄壁样, 分析了沉积态的凝固组织, 并进行了热处理和力学性能测试. 研究表明, 激光熔化沉积Rene95镍基合金的凝固组织为外延生长的定向凝固组织, 其一次枝晶间距在20 μm左右, 二次枝晶臂细小甚至退化, 元素偏析较轻; 通过适当的热处理后, 合金中γ′沉淀相的体积分数明显增加, 合金的显微硬度由沉积态的HV_(0.1) 500提高到HV_(0.1) 540; 经过热处理后, 激光熔化沉积Rene95合金的室温抗拉强度为1247 MPa, 较粉末冶金C级水平略低, 而沿沉积高度方向的延伸率为16.2%, 高于粉末冶金A级水平. 相似文献
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纳米级球形In2O3(SnO2)粉末的制备及性能研究 总被引:5,自引:0,他引:5
采用化 学液相 共沉淀,以 铟、四氯 化锡为 原料,通过 选择沉 淀介质和 控制一定 的工艺 ,制备了球形的 I T O 粉料。用 T E M 、 B E T 等法对 所制粉料 进 行了 表征 。结 果表 明, 所制 粉料 分 散性 好,粒径约为 16 n m 。 相似文献
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It is shown that high-porosity materials based on tungsten and nickel that have been made with the use of pore-forming agents show an increase in specific conductivity as the ratio between the dimensions of the metal particles and those of the pore-forming ones increases. This result is explained from the viewpoint of the fractal dimensions and the percolation threshold. 相似文献
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The task of monitoring porous materials is formulated. Principles for developing and using nondestructive acoustic methods for monitoring the structure and physicomechanical properties of porous materials are suggested and discussed. It is noted that the solution of each monitoring problem for porous materials requires an individual, often nontraditional, approach and its success is determined by the possibility of developing theoretical or experimental correlation dependences between the acoustic and material properties sought. It is shown that it is possible from the results of measuring propagation velocity and elastic wave damping factors to determine parameters such as elasticity, inelasticity, porosity, defectiveness, the size of structural elements, anisotropy, and property inhomogeneity. 相似文献
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采用微波造孔活化技术,在不添加造孔剂的情况下,对赤泥实现造孔活化和强化来制备新型吸附材料。利用XRD、SEM、FTIR等手段对制备的吸附材料进行了表征。结果表明,该粒状赤泥经活化后,孔道清晰,所制备的吸附材料为多孔制,表面具有更多的吸附活性孔位。 相似文献
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从化学成分、显微组织、断口形貌、力学性能方面对JFE—HITEN610U2L钢进行了研究。结果表明:该钢以低碳高锰,加入微量镍、铬、钼、钒、铌等元素的合金化方式,通过适当的控制热加工工艺,获得了以针状铁素体为主的混合组织,表现出良好的力学性能。当针状铁素体条束比较粗大时,-50℃冲击试样的断裂方式从韧窝断裂转变为解理断裂,韧性明显下降。 相似文献
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The role of Mg in alloy/718 has been systematically investigated. Mg raises not only high temperature tensile and stress-rupture ductilities but also increases considerably smooth and notch stress-rupture life. Mg containing alloy 718M is free of stress-rupture notch sensitivity. Mg improves creep and fatigue interaction properties (LCF or cyclic stress rupture) at any grain size. The basic role of Mg is equilibrium segregation at grain boundaries which helps to change continuous grain beundary (5-Ni3Nb morphology to discrete globular form which has a retardation effect on intergranular fracture. Mg promotes the change from intergranular to transgranular fracture mode. 相似文献
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新型钴基高温合金的组织结构与力学性能 总被引:3,自引:0,他引:3
对新设计的三种新型钴基高温合金的组织结构及性能进行了研究.结果表明:钨作为合金的主要固溶元素,其含量必须控制在17.0%~18.5%的范围内,才能有效地起到固溶强化作用.过多的钨元素将形成大量的析出相,晶粒也因此而细化,虽然合金的室温强度会有所提高,但是在1200℃高温下,变得较为薄弱的大量晶界却使强度明显降低. 相似文献