占位剂K_(2)SO_(4)对NiCu合金多孔膜孔结构的影响  

Effect of K_(2)SO_(4)space-holder on pore structure of NiCu alloy porous membrane

作　　者：冯路利 喻林萍[2] 干庆展 高海燕[1] 贺跃辉[1] FENG Luli;YU Linping;GAN Qingzhan;GAO Haiyan;HE Yuehui(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;School of Chemistry and Biology Engineering,Changsha University of Science&Technology,Changsha 410114,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]长沙理工大学化学与生物工程学院,长沙410114

出　　处：《粉末冶金材料科学与工程》2021年第2期147-154,共8页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51774336)。

摘　　要：以Ni元素粉末为原料,K_(2)SO_(4)粉末为占位剂,将Ni-K_(2)SO_(4)混合粉末加入聚乙烯缩丁醛(PVB)乙醇溶液中制成浆料,刮涂在Cu箔上,利用Kirkendall效应,经真空烧结制备多孔NiCu合金膜。研究K_(2)SO_(4)含量对NiCu合金多孔膜收缩率、透气度、孔径、宏观和微观形貌的影响。结果表明:随Ni-K_(2)SO_(4)混合粉末中的w(K_(2)SO_(4))增加,多孔膜的透气度先增大后减小。当w(K_(2)SO_(4))<40%时,随w(K_(2)SO_(4))增加,膜层的烧结收缩率减小,透气度增大,最大达到2361 m3/(m2·h·kPa),最大孔径在45μm左右变化不大;w(K_(2)SO_(4))大于40%时,多孔膜的透气度下降,孔径明显减小;当w(K_(2)SO_(4))>60%,膜层透气度低于测试仪器下限。适量的K_(2)SO_(4)通过在涂覆层中的占位作用阻碍Ni颗粒烧结致密化,提高多孔膜的透气度,但过量的K_(2)SO_(4)会在烧结过程中阻断Cu原子向Ni粉层扩散,使Cu箔上难以形成通孔,透气度大幅降低。The Ni-K_(2)SO_(4)mixed powder,in which Ni element powder is the raw material,and K_(2)SO_(4)powder is the space-holder,is added into the polyvinyl butyral(PVB)ethanol solution to make a slurry,which is coated on the Cu foil.NiCu alloy porous membrane was prepared basing on Kirkendall effect by vacuum sintering.The influence of K_(2)SO_(4)contenton on area shrinkage,permeability,pore size,macro and micro morphologies of porous membrane and the influence of K_(2)SO_(4)on the pore structure of porous membranes at different temperatures were investigated.The effect mechanism of K_(2)SO_(4)on pore structure of the porous alloy membrane during sintering process was also studied.The results show that with the increase of w(K_(2)SO_(4))in Ni-K_(2)SO_(4)mixed powder,the permeability of porous membrane first increases and then decreases.When the mass fraction of K_(2)SO_(4)is lower than 40%,with the increase of K_(2)SO_(4)content,the shrinkage rate of the film decreases and the permeability increases.The maximum permeability is 2361 m3/(m2·h·kPa).The maximum pore diameter of the sample with little change is about 45μm.When the w(K_(2)SO_(4))is more than 40%,the permeability and pore diameter of the porous film both decrease obviously.When the w(K_(2)SO_(4))is more than 60%,the permeability of the film layer is lower than that of the lower limit of the test instrument.Proper amount of K_(2)SO_(4)can improve the permeability of porous alloy membrane through hindering sintering densification based on the space occupying effect in the Ni coating,but excessive amount of K_(2)SO_(4)will block the diffusion of Cu atoms to Ni powder layer,which makes it difficult to form through-pores on the Cu foil,resulting in a significant decrease in permeability.

关 键 词：K_(2)SO_(4) 多孔膜 NiCu合金 透气度 孔径 占位剂 

分 类 号：TB31[一般工业技术—材料科学与工程]