Ti基非晶复合材料马氏体相变的研究

发布时间：2018-04-01 05:23

  本文选题：Ti基非晶合金　切入点：相组成　出处：《大连交通大学》2015年硕士论文

【摘要】：本论文主要是在具有较大玻璃形成能力的Ti Ni Cu合金体系中添加Nb、Zr和Sn元素。采用铜模喷铸法和甩带法制备出了Ti Ni Cu Nb、Ti Ni Cu Zr非晶复合材料,利用电弧熔炼制得Ti Ni Cu Zr Sn合金,利用XRD、DSC和电阻法等方法对合金的相组成和马氏体相变温度等分析测试,讨论了不同的合金元素、冷却速度和热处理温度对合金组织结构与相变温度的影响。含量为4at.%Nb元素及4at.%和5at.%Zr元素能够促进Ti Ni Cu Nb/Zr合金发生马氏体相变,合金中主要有B2相和B19相,在升温和降温过程中发生一阶B2 B19相变。Nb能促进合金析出枝晶相β-Nb相,显著降低Ms点,增大相变热滞后ΔT;随着Zr含量的增加,Ti Ni Cu Zr合金的Ms点先降低后升高,热滞后ΔT先增大后减小。Ti50Ni25Cu25非晶合金板条发生一阶B2 B19相变,Ti45Ni25Cu25Zr5非晶合金板条发生B2 R B19'二阶相变。喷铸后合金马氏体相变点都显著降低,相变滞后增加。经过300℃和500℃时效后相变点和相变滞后变化不大,合金具有较稳定的马氏体相变过程。甩带法和喷铸法都能够制得Ti基非晶复合材料。Nb元素降低合金非晶形成能力,4at.%和5at.%的Zr元素能够提高非晶形成能力。经过时效处理后,Ti基非晶合金发生一定的晶化行为,析出晶体相。Ti Zr Cu Ni Sn五种合金主要晶体相为B2相、tP4 TiCu相和(Ni,Ti)相,Sn元素促进枝晶相tP4 TiCu相的产生。Sn元素含量为3.1at.%的三种合金只在升温过程中发生B19 B2逆相变,合金具有稳定的马氏体相变过程,Cu元素逐步代替Ni元素时,逆相变温度As升高。Sn元素含量为3at.%的Ti50Ni25Cu16Zr6Sn3合金发生B2 R B19'二阶相变,Ti50Ni16Cu25Zr6Sn3合金发生B2 B19相变。Cu元素代替Ni元素含量为9at.%时,Ms点和Mf点下降,合金的相变滞后有很小的减小。
[Abstract]:In this paper, NB, Zr and Sn elements were added to Ti / Ni / Ni / Cu alloy system with high glass-forming ability. Amorphous composites were prepared by copper mold spray casting method and strip throwing method. The phase composition and martensite transformation temperature of the alloy were analyzed and measured by means of XRDX DSC and resistance method, and different alloy elements were discussed, and the alloy was prepared by electric arc melting, and the alloy was prepared by arc melting, and the phase composition and martensite transformation temperature of the alloy were measured by means of XRDX DSC and resistance method. The effects of cooling rate and heat treatment temperature on the microstructure and transformation temperature of the alloy were studied. The contents of 4at.%Nb, 4at.% and 5at.%Zr can promote martensitic transformation in Ti Ni Ni Cu Cu Nb/Zr alloy, and the main phases in the alloy are B2 phase and B19 phase. In the process of heating and cooling, the first order B 2 + B 19 phase transformation. NB can promote the precipitation of dendritic phase 尾 -Nb phase, decrease the Ms point and increase the phase transformation thermal hysteresis 螖 T, with the increase of Zr content, the Ms point of the alloy decreases first and then increases. The thermal hysteresis 螖 T increases first, then decreases. Ti50Ni25Cu25 amorphous alloy lath takes place the first order B 2 + B 19 phase transformation of Ti45Ni25Cu25Zr5 amorphous alloy strip. The B 2 / R B ~ (19') second order phase transformation occurs. The martensite transformation point of the alloy decreases significantly after spray casting. Phase transition hysteresis increases. After aging at 300 鈩，

本文编号：1694170