孔内压力对规则多孔Cu-1.3Cr合金气孔形貌的影响  

Effect of pressure in pore on pore morphology of porous Cu-1.3Cr alloy with directional pores

作　　者：宋群玲[1] 李瑛娟[1] 滕瑜[1] 金青林[2] 李芬锐 SONG Qunling;LI Yingjuan;TENG Yu;JIN Qinglin;LI Fenrui(Faculty of Metallurgy and Materials,Kunming College of Metallurgy,Kunming 650033,China;Faculty of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]昆明冶金高等专科学校冶金材料学院,昆明650033 [2]昆明理工大学材料科学与工程学院,昆明650093

出　　处：《航空材料学报》2022年第4期95-103,共9页Journal of Aeronautical Materials

基　　金：云南省教育厅基金项目(2019J0894);有色金属先进成型技能大师工作室项目。

摘　　要：在氢气气氛中定向凝固制备规则多孔Cu-1.3Cr合金,并对其气孔形貌进行研究。结果表明:随着氢气压力从0.1 MPa增加到0.6 MPa,孔隙率从18%增加至44%,而气孔直径从3.24 mm降到0.44 mm。理论分析表明:随着气孔的生长,气孔长度的增加会造成气孔内部压力显著下降。对于粗大的气孔(气孔间距较大),气孔压力的下降会导致固液界面处的液相倒流进入气泡,形成竹节状的气孔形貌。而对于细小的气孔(气孔间距较小),相邻气孔之间的压力差会促使较短气孔中的氢气向较长的气孔传输,一旦长短两个气孔发生接触则会直接合并在一起。Cu-1.3Cr alloys with directional pore structure were fabricated under hydrogen atmosphere.The pore morphology during the solidification is investigated.It is found that the porosity is increased from 18%to 44%and the average pore diameter was decreased from 3.24 mm to 0.44 mm when the hydrogen pressure varies from 0.1 MPa to 0.6 MPa.Theoretical analysis shows the gas pore pressure drops significantly during the growth of pore.For a coarse pore,the drops of pore pressure will result in a backflow of the melt from solidification interface into gas pore,and this will result in a“bamboo”like structure.For small gas pores,the pressure difference between two neighboring gas pores drives the hydrogen gas from the short one to the long one.This is the reason that a short pore more easily coalesce with a long pore.

关 键 词：铜铬合金 金属-氢共晶 气孔压力 气孔形貌 

分 类 号：TG146[一般工业技术—材料科学与工程]