Fe和Nb对TiNi形状记忆合金环双程记忆效应的影响

研究了预变形和热循环对Ti50.8Ni49.2及加入Fe和Nb后合金环的双程记忆应变影响。结果表明:在马氏体状态进行10.4%~13.8%的预变形,TiNi合金环随循环次数增加,双程记忆应变增大,在13.8%预变形和4次循环得到4.15%最大值;加入Fe和Nb后,在10.71%~15.18%的变形范围,合金环的双程记忆应变先增后降,其最大值分别为3.14%和2.56%。在变形量和循环次数相同时,TiNi合金环的记忆应变最高,当变形量和循环次数超过12.50%和2以后,TiNiFe合金环的双程记忆应变快速上升,其双程记忆应变超过TiNiNb合金环的。

Influence of Fe and Nb Addition on Two-Way Shape Memory Effect of TiNi Shape Memory Alloy Rings

The influence of pre-strains and number of thermal cycling on the two-way shape memory strains of TiNi,TiNiFe and TiNiNb alloy rings were investigated to provide theoretical basis for their applications in engineering.The results indicate that the two-way memory strains of TiNi alloy rings deformed at temperature less than Mf point increase with the increase of thermal cycling number within the range of 10.4%~13.8% pre-strains.The maximum two-way memory strain of 4.15% is obtained at pre-strain of 13.8% and thermal cycling number up to 4.And when Fe or Nb atoms are added to TiNi alloys,the two-way memory strains of alloy rings first increase and then decrease at the ranges of 10.71%~15.18% pre-strains,their maximums are 3.14% and 2.56%,respectively.At the same pre-strain and thermal cycling number,the two-way memory strains of TiNi alloy rings are the greatest,after pre-strain and cycling number are more than 12.50% and 2,the two-way memory strains of TiNiFe rings rapidly rise and are greater than that of TiNiNb alloy rings.