Development of A New Type of Functional NiAl-base Alloys

具有b2型（C_sC1）结构的镍钴铝化物β相具有高温强度高、抗氧化性好、形状记忆性好、阻尼能力强等多种功能的新型材料的潜力。然而，其延展性的不足限制了其作为功能材料的应用。本课题的目的是开发一种新型的β基多功能材料，通过微观组织控制来提高其延展性。热力学分析通过实验确定了Ni-Al-Mn、Ni-Al-Co和Ni-Al-Fe体系中富ni部分的相平衡，并根据实验数据进行了热力学分析。高温材料根据热力学分析的信息，采用显微组织控制的方法，采用常规的制备方法结合热机械热处理，研制出了具有优良抗氧化性能和高温强度的延展性γ′(l12)+ β两相合金。用DSC法测定了Ni-Al-X （X: Ti， V,Cr, Mn, Fe, Co， Cu等）体系β相B2*L1_0 （Ms）的相变温度。结果表明，Mn、Fe和Co的加入有助于提高Ms温度。利用这些Ms和相平衡数据，在Ni-Al-Fe-Mn四元体系中开发出了在100 ~ 600℃高温下工作的韧性γ (Al)+ β两相形状记忆合金。两相形状记忆合金不仅具有较高的阻尼能力，而且屈服强度也高于其他阻尼材料。

The beta phase of nickel and cobalt aluminides with B2-type (C_sC1) structure have the potential to serve as a new type of materials with multi-functional properties such as high temperature strength, good oxidation resistance, shape memory, high damping capacity, stc. However the lack of ductility limits their application as the functional materials. The aim of this project is to develop a new type of beta base multi-functional materials improved ductility by microstructural control.1.Thermodynamic AnalysisThe phase equilibria of the Ni-rich portion in the Ni-Al-Mn, Ni-Al-Co and Ni-Al-Fe systems have been experimentally determined, and thermodynamic analysis on basis of the experimental data have been done.2.High Temperature MaterialsBy means of microstructural control due to the information of the thermodynamic analysis, ductile gamma'(L1_2)+beta two-phase alloy which has both excellent oxidation resistance and high temperature strength has been developed by the conventional fabrication method combined with a thermomechanical heat treatment.3.Shape Memory and Damping MaterialsMartensitic transformation temperatures in the beta phase B2*L1_0 (Ms) of the Ni-Al-X (X : Ti, V,Cr, Mn, Fe, Co, Cu, etc.) systems were determined by DSC.It was clarified that adding Mn, Fe and Co are useful to increase the Ms temperature. By means of these data of Ms and phase equilibria, ductile gamma(Al)+beta two-phase shape memory alloys which operate at high temperatures between 100 and 600ﾟC have been developed in the Ni-Al-Fe-Mn quaternary system. These two-phase shape memory alloys show not only high damping capacity, but also higher yield strength than the other damping materials.