金属合金等温相变的体激活能及相变机制 Ⅱ．β黄铜等温相变  

OVERALL ACTIVATION ENERGY OF ISOTHERMAL TRANSFORMATION IN METAL ALLOY AND ITS MECHANISM Ⅱ.Isothermal Transformation inβBrasses

作　　者：康沫狂[1] 张明星 刘峰[1] 朱明[1] 

机构地区：[1]西北工业大学材料学院,西安710072 [2]Division of Materials,School of Engineering,University of Queensland,Brisbane,QLD 4072,Australia

出　　处：《金属学报》2009年第1期32-36,共5页Acta Metallurgica Sinica

摘　　要：与钢相似,β黄铜等温处理获得的片状α_1(贝氏体)和棒状α都具有自己的C曲线;各转变初期均能获单一相,而转变中、后期通常可获相邻两相的复合体.必须用单一相和Arrhenius关系求相变产物的体激活能.用体激活能、相的形貌和体自由能变化相结合能可诠释下述论点:片状α_1(贝氏体)是溶质原子扩散控制下母相β′中的贫溶质区,进行"军队型"原子无扩散马氏体样切变相变;棒状α是溶质原子扩散控制下母相β′中的最贫溶质区,发生"平民型"原子无扩散界面控制相变.Similarly to steels, in the isothermally treated β brasses, the plate-like α1 （bainite） and rod-like a have all themselves C curves. A single phase is always produced in the primary stage, whereas the nearby two-phase complex is usually produced in the medium or final stage of the transformation. Only a single phase and Arrhenius equation must be used to deduce the overall activation energy for the transformation product. By a combination of overall activation energy, morphology and change of free energy, it can be explained that the plate like α1 （bainite） transformation mechanism follows military atom diffusionless martensite-like shear, occurring in solute-depleted region controlled by solute atom diffusion in parent phase β＇, and the rod-like α phase results from civilian atom diffusionless interphase control transformation, occurring in the most solute-depleted region controlled by solute atom diffusion in parent phase β＇.

关 键 词：片状α1(贝氏体) 棒状α 体激活能 马氏体样切变 界面控制相变 β黄铜 

分 类 号：TG111.5[金属学及工艺—物理冶金]