(合肥工业大学 材料科学与工程学院，合肥 230009)
摘 要: 以Ti-15-3合金热压缩变形显微组织的TEM像作为研究对象，基于Matlab软件平台，开发了图像处理及分形分析程序，采用盒维数法对不同变形温度、变形程度和变形速率下的显微组织形貌进行了分形分析。结果表明：Ti-15-3合金热塑性变形显微组织具有分形特征，可以采用分形维数对其形貌进行定量描述，且显微组织的分形维数随着变形温度的升高而减小，随着变形程度和变形速率的增大而增大；随着流变应力的增大，与之相对应的显微组织的分形维数增大；分形维数反映了热变形过程中软化过程进行的程度和金属变形抗力的大小；分形维数越小，软化过程进行得越充分，金属的变形抗力越小。
关键字: Ti-15-3合金；热变形；显微组织；分形
（School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China）
Abstract:On the basis of Matlab software, the image treatment and fractal analysis by box counting program were developed. The systematic fractal analysis of TEM images of Ti-15-3 alloy after compression deformation at different temperatures, strains and strain rates were conducted. The results show that the hot deformed microstructures of Ti-15-3 alloy have the characteristic of fractal and can be described quantitatively by fractal dimension. The fractal dimension decreases with increasing temperature and increases with increasing strain and strain rate. Furthermore, with increasing flow stress, the fractal dimension of corresponding microstructure increases. The fractal dimension reveals the degree of dynamic softening during hot deformation and the magnitude of deformation resistance. With decreasing fractal dimension, the softening degree increases and the deformation resistance decreases.
Key words: Ti-15-3 alloy; hot deformation; microstructure; fractal
