Cn—Zn—Al合金贝氏体预相变的恒温内耗研究

A STUDY OF ISOTHERMAL INTERNAL FRICTION ASSOCIATED WITH PREBAINITE TRANSITION IN Cu-Zn-Al ALLOY

用微机控制的倒扭摆内耗仪,对分级淬火后的Cn-22.5at％Zn-9.3at％Al—1at％Mn合金进行了内耗测量。结果表明:在160℃附近停止升温,并进行恒温内耗测量,发现内耗(Q^(-1))随保温时间而上升,模量变硬。结合电镜观察证实这一过程与溶质偏聚和沉淀有关。随着恒温时间的延长,出现Q^(-1)峰和模量极小。并伴有零点漂移。这是β母相→正交9R的切变型贝氏体转变引起的。

The measurement of internal friction (Q^(-1)) is carried out in this paper for Cu-22.5 at％ Zn-9.3 at％ Al-1 at％ Mn alloy by using an inversed torsion pendulum controlled by microcomputer. The results show that, when isothernal is at about 160℃, the Q^(-1) and modulus increase with an increase in isothermal time. The TEM observation has confirmed that this process is associated with the segregation of the solute atoms. When isothermal time increases further, an internal friction peak relaled to the phase transition from parent β to 9R bainite and modulus minimum accompanied with zero point shift which is similar to the characteristic of martensite transformation appears.