(合肥工業(yè)大學 材料科學與工程學院，合肥 230009)
摘 要: 以Ti-15-3合金熱壓縮變形顯微組織的TEM像作為研究對象，基于Matlab軟件平臺，開發(fā)了圖像處理及分形分析程序，采用盒維數(shù)法對不同變形溫度、變形程度和變形速率下的顯微組織形貌進行了分形分析。結果表明：Ti-15-3合金熱塑性變形顯微組織具有分形特征，可以采用分形維數(shù)對其形貌進行定量描述，且顯微組織的分形維數(shù)隨著變形溫度的升高而減小，隨著變形程度和變形速率的增大而增大；隨著流變應力的增大，與之相對應的顯微組織的分形維數(shù)增大；分形維數(shù)反映了熱變形過程中軟化過程進行的程度和金屬變形抗力的大小；分形維數(shù)越小，軟化過程進行得越充分，金屬的變形抗力越小。
關鍵字: Ti-15-3合金；熱變形；顯微組織；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
