机构地区:[1]有研工程技术研究院有限公司,北京101407 [2]有研科技集团有限公司生物冶金国家工程实验室,北京100088 [3]有研资源环境技术研究院(北京)有限公司,北京101407 [4]北京有色金属研究总院,北京100088
出 处:《稀有金属》2022年第9期1215-1224,共10页Chinese Journal of Rare Metals
基 金:国家重点研发计划项目(2017YFB0305403)资助。
摘 要:金属钛、锆具有较强的氧亲和力,在冶炼、加工过程中易增氧导致材料性能下降。本研究采用了一种简单、易行的固态脱氧方法——外部吸收法,对金属钛、锆进行脱氧,并考察了脱氧过程中各种因素对脱氧效果的影响。研究结果表明,在Ca-CaCl_(2)脱氧体系下,脱氧温度为900℃,脱氧时间24 h,CaCl_(2)和金属Ti,Zr的质量之比为8∶1,金属Ca加入量为其在CaCl_(2)熔盐中溶解度的200%,并添加CaCl_(2)质量5%的KCl作为助熔剂,脱氧方式为金属样品、金属Ca,CaCl_(2)直接混合的条件下,金属Ti,Zr的氧含量分别由起始的670×10^(-6)和800×10^(-6)降至脱氧后的120×10^(-6)和70×10^(-6)。在Ca-CaCl_(2)脱氧体系中,氧会在熔盐中不断积累使氧的活度提高,脱氧效果产生波动。本文提出通过引入比Ca更亲氧的金属Y,来降低熔盐中氧的活度,改善Ca-CaCl_(2)体系脱氧效果不稳定的问题。实验结果表明,Y在脱氧过程中会生成Y_(2)O_(3)并和过量金属Y组成Y-Y_(2)O_(3)平衡,Y-Y_(2)O_(3)平衡可以将熔盐中氧的活度“锚定”在较低水平,从而将Ti,Zr样品的氧含量稳定控制在100×10^(-6)以下,改善了Ca-CaCl_(2)体系的脱氧效果。Low oxygen content and high purity Ti and Zr were the key materials in laser components,large-scale integrated circuits,hydrogen isotope treatment,high temperature alloys and other fields.The physical and chemical properties of Zr and Ti were very sen-sitive to the interstitial oxygen.Because high oxygen content can easily lead to many problems or even safety risks,such as embrittle-ment and hardening of materials,defects of evaporative coating and deterioration of hydrogen absorption and discharge properties.However,both of Zr and Ti had strong oxygen affinity and high solubility of oxygen.During smelt,hot working and working condition,the oxygen concentration will inevitably increase which will degrade the material performance.Currently used high purity metal prepa-ration technology,such as vacuum EB-melting,vacuum arc melting,electrolytic refining cannot achieve the in-depth deoxidation of ti-tanium and zirconium.Therefore,high oxygen content had always been a difficult problem in the process of producing high purity tita-nium zirconium.To solve the problem,a simple solid state deoxidation method—“external gettering process”was employed to deoxi-dize Ti and Zr.The Ca-CaCl_(2)system a typical external gettering system was employed.Because it had strong deoxidation ability,good kinetic conditions and stable physical and chemical properties,which was suitable to the deoxidation of Ti and Zr.The influence of var-ious factors on deoxidation effect,such as temperature,deoxidation time,the mass ratio of CaCl_(2)to metal specimens,deoxidation mode during the deoxidation process were investigated systematically by chemical equilibrium technique.In addition,the effect of ad-ditives on deoxidation capacity of the Ca-CaCl_(2)system was also discussed.It was shown that the thermodynamic and kinetic conditions of external gettering deoxidation were opposite to each other.Therefore,the selection of actual deoxidation temperature needed to take into account the thermodynamic conditions and dynamics,find a balance point
关 键 词:钛 锆 外部吸收脱氧法 Ca-CaCl2体系 钇
分 类 号:TF841.4[冶金工程—有色金属冶金]
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