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挤压316L金属蜂窝的烧结及其组织性能研究 总被引:1,自引:1,他引:0
以金属粉末、粘结剂为原料,经炼料制成膏状挤压料,通过挤压模成型为蜂窝状,再经高温烧结制备成316L不锈钢蜂窝.研究了烧结气氛、烧结温度对蜂窝烧结组织结构的影响,并对烧结后的蜂窝进行力学性能测试.结果表明,在氢气中烧结的316L蜂窝组织,金属颗粒间形成烧结颈,呈网状连接在一起,并随温度升高颗粒合并长大成晶粒,基体组织为Fe-Cr-Ni-C(γ-Fe)固溶体,第二相球形颗粒为富含硅的低熔点化合物;在真空中烧结,金属颗粒表面形成氧化物Fe2Cr4O4、Cr2O3,以及SiO2,大量的表面氧化物阻碍了金属粉末颗粒的结合,直接影响烧结蜂窝的强度,致使烧结蜂窝强度远低于氢气中烧结的蜂窝.在氢气中烧结的316L金属蜂窝,其径向抗压强度可达40~50 MPa,远高于目前广泛应用的陶瓷蜂窝载体,是作为载体材料的一种理想选择. 相似文献
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以纯铁粉、铬粉、铝粉为原料,采用粉体增塑挤压-烧结工艺制备Fe-25Cr-5Al金属蜂窝,研究不同的烧结温度和时间条件下烧结蜂窝的收缩率、表观密度和组织结构特征.研究表明,随烧结温度的升高,蜂窝的收缩率和表观密度增大,径向收缩率的范围为5.6%~12.3%,表观密度的范围为0.98~1.09g/cm3.在1250℃烧结时,随烧结时间的延长,蜂窝的收缩率和表观密度也随之增大,径向收缩率的范围为6.5%~12.1%,表观密度的范围为0.85~1.02g/cm3.烧结组织为Fe-Cr固溶体(α-Fe)基体,少量Fe-Al,Cr-Al间化合物及Cr2O3,Al2O3. 相似文献
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为制备性能优良的Al_2O_3/430L复合型蜂窝载体材料,本文以430L不锈钢合金粉末、Al_2O_3粉末、粘结剂为原料,采用粉末增塑挤压技术挤压成形,并在1 100℃真空中烧结2 h获得Al_2O_3/430L复合型蜂窝材料.借助SEM、XRD及万能试验机,研究了添加Al_2O_3对Al_2O_3/430L复合型蜂窝材料的组织与性能的影响.研究表明:金属粉末颗粒在烧结过程中结合形成的基体组织为α-Fe(Cr),在基体晶粒间孔隙处和表面弥散分布着Al_2O_3颗粒.添加少量的Al_2O_3可提高烧结密度,制件表面光滑.随着Al_2O_3添加量增加,蜂窝材料表面负载催化涂层的能力增强;抗压强度随Al_2O_3添加量的增加先升高后降低,在Al_2O_3含量为2.5wt.%时,最大抗压强度达27 MPa.添加2.5wt.%Al_2O_3所制备的Al_2O_3/430L复合型蜂窝材料力学性能最佳、表面负载催化涂层的能力优良. 相似文献
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以410L和430L不锈钢粉为基体,以CaCl2为造孔剂,采用粉末冶金烧结溶解法制备出不同孔隙率的410L和430L泡沫钢并分析比较其组织和性能。结果表明:410L和430L泡沫钢的基体组织都是α-Fe;在相同的腐蚀条件下430L不锈钢的抗腐蚀性更强;在烧结过程中410L泡沫钢孔壁表面的氧化程度比430L泡沫钢严重;在准静态压缩变形过程中孔隙率为73%~83%的410L泡沫钢屈服应力为22.06~5.45 MPa,相同孔隙率的430L泡沫钢其屈服应力为56.77~10.44 MPa,430L泡沫钢的抗压强度是410L泡沫钢的2~3倍;应变量为50%时,孔隙率为73%~83%的410L泡沫钢单位体积的能量吸收值为6.12~2.90 MJ/m3。应变量为50%时,孔隙率为72%~83%的430L泡沫钢其单位体积的能量吸收值为40.35~8.25 MJ/m3。430L泡沫钢的单位体积能量吸收值约为410L泡沫钢的3~5倍。 相似文献
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The sintering technology for mixed powedered extrusion rods of different proportions of stainless steel to magnesia partially stabilized zirconia(PSZ) was investigated..The effects of some sintering parameters including holding time ,atmosphere and protective gas pressure on shrinkage,relative density,micostructure,micro-Vickers hardness and compression strength of sintered samples were mainly researched.The experimental results are as follows(1)The shrinkage and the relative density of the sintered samples decrease as increasing stainless steel content in the composite,except for the xase containing 90 percent of stainless steel;(2)The porosity in PSZ matrix rises as increasing the stainless steel content in the composite;(3)Longer sintering holding time ,higher sintering vacuum and gas-pressure sintering process not only enhance the relative density ,but also improve microstructure of composite;(4)Micre-Vickers hardness of PSZ matrix decreases as increasing stainless steel content,while that of stainless steel particles in sintered samples varies unnoticeably. 相似文献
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采用溶剂脱脂和热脱脂相结合的方法,研究了超细316L不锈钢粉末注射成形坯的脱脂工艺。注重考察了升温速度和保温时间对不锈钢注射坯的热脱脂工艺的影响。研究表明注射成形坯经正己烷溶剂脱脂后,石蜡组元全部被脱除。其它组元在后续的热脱脂中被去除,确定了优化的升温速度和保温时间,试样没有出现缺陷,并缩短了脱脂周期,该周期大约为10小时。 相似文献
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Qiang Zhang) Xingpeng Guo) Nengli Dai) Peixiang Lu) ) Department of Chemistry Chemical Engineering Huazhong University of Science Technology Wuhan China ) Wuhan National Laboratory for Optoelectronics School of Optoelectronics Science Engineering China 《材料科学技术学报》2009,25(2):187-193
The 304 stainless steel (SS) microcantilever specimens with dimensions of 30 μm×30 μm×50μm (thickness×width × length) were fabricated by femtosecond (fs) laser. The microsized cantilevers of good quality with structure and dimensions according commendably with that of the designed cantilever were obtained. The result shows that fs laser micromachining is a promising method for directly fabricating metallic microcomponents.Corrosion and fatigue properties of microsized specimens were carried out on the microsized 304 SS cantilever beams by a newly developed fatigue testing machine. The results show that the microsized 304 SS specimens appear to have an improved resistance towards localized corrosion compared to ordinary-sized 304 SS specimens after the static corrosion testing. The testing result shows that the presence of corrosive solution reduces the fatigue lifetime of the 304 SS specimen by a factor of 10-100. The maximum bending loads measured by fatigue testing machine decrease rapidly at the terminal stage of environment assisted fatigue testing.Corrosion fracture first occurred at the range of notch with a higher tensile bending stress, and exhibited clear evidence of trans-columnar fracture detected by SEM (scanning electron microscopy). 相似文献
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316L不锈钢粉真空松装烧结的研究 总被引:1,自引:0,他引:1
研究了316L不锈钢粉注射成形等低压成形工艺的粉末真空松装烧结行为及其影响因素。通过添加石墨实现脱氧控碳,分析比较了气,水雾化粉真空松装还原烧结行为的差异。 相似文献
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进行316L不锈钢在600℃圆路径下不同应变范围的低周疲劳实验,用透射电子显微镜(TEM)观察疲劳失效断口附近的显微组织,研究了位错结构的路径相关性、幅值相关性以及动态应变时效(Dynamic strain aging,DSA)的路径相关性。结果表明:在室温和600℃的单轴加载变形以平面滑移方式为主,生成了脉络状位错结构;而在圆路径下则生成等轴胞状位错结构,显著降低了材料抵抗变形的能力,在600℃等效应变范围为1.0%条件下的疲劳寿命比单轴路径降低了81%。同时,在圆路径下材料形成胞状位错结构所需最小等效应变范围比单轴的低。600℃圆路径下的DSA效应更为完全,在等效应变范围为1.0%的条件下最大应力跌幅比单轴路径增大了680%;同时,压缩阶段的DSA现象更为显著,锯齿类型由A型经过B型过渡到C型。 相似文献