含硼的Cu-Zn-Al合金中母相晶粒度和有序度对M_s的影响

INFLUENCE OF GRAIN SIZE AND ORDERING DEGREE OF PARENT PHASE ON M_s IN A Cu-Zn-Al ALLOY CONTAINING B

研究了母相平均晶粒尺寸和有序度对Cu-25.62Zn-3.97Al-0.0018B(wt-%)形状记忆合金热弹性马氏体相变点的影响。从相变热力学出发,得到马氏体相变点和晶粒尺寸的平方根的倒数成线性关系,并且随晶粒尺寸增大,马氏体相变点升高,与电阻法测得的结果符合很好。运用Landau理论,得到马氏体相变点和母相有序度的定量关系式,与X光衍射和电阻法试验的结果符合较好。求得试验用合金母相DO_3有序化的激活能约为46kJ/mol。

Based on the thermodynamics of phase transformation, a linear relation-ship between the starting temperature of martensitic transformation and the recipro-cal of the squareroot of grain size has been obtained, i. e. M_s temperature decreaseswith the increasing grain size. It shows a good agreement with the results of elec-tric resistance measurements. Application of Landau's theory gives a quantitative re-lationship between M_s temperature and the ordering parameter of the parent phase,which is well confirmed by the results of X-ray diffraction and electric resistancemeasurements. The activation energy of the DO_3 ordering process in the parent phaseof the alloy is calculated to be 46 kJ/mol.