Papers by Author: Ming Wen

Abstract: Spark plasma sintering (SPS) technology was used in-situ to fabricate the Ti₂AlC/TiAl (Nb, B) composites. And the composites were treated by rapid heat treatment. which had many advantages, such as heating-up quickly, short holding time and relatively slow cooling. The hidden relationship between images could be reflected by Multi-fractal spectrum, which also could show irregularity apparently. In this paper, the SEM images which fabricated after rapid heat treatment were researched by multifractals. And the parameter was calculated by MATLAB through anglicizing the multi-fractal spectrum theory. There was only small fluctuate between lnχq (r) and lnr when r=0.00625, and lnχ_{q (r)} and lnr had well linear relationship in spite of the value of q. After the rapid heat treatment at T=1403 K, the correlation coefficient between τ (q) and q reached 99.99% . The trend of D (q) and q turned to be gently, and the fracture appeared uniformity, and these SEM images were single fractures. τ (q) and q show nonlinear relationship in q∈[-3,-1], and there was one observe steep.The clock shape relationship between the α and f (α) revealed good symmetry of spectrum, wider spectral width, uneven distribution of the fracture, multi-fractal feature clearly, and obvious characteristic of multi-fractal. Key words: multi-fractal spectrum, rapid heating heat treatment, fractal dimension

Abstract: The SEM images of Ti₂AlC/TiAl materials with different samples showed different fractal dimension.In Multi-fractal spectrum, the parameter is calculated by the multi-fractal spectrum theory. Without r=0.00625, giving rise to the small fluctuate, lnχq(r) and lnr shows the well linear relationship in spite of the value of q. τ (q) and q show nonlinear relationship and the protuberance existed in q∈[-3,-1], D(q) and q turn to be more steep, at last the clock shape relationship between the α and f(α) reveals the good symmetry of spectrum, uneven distribution of the fracture, multi-fractal feature clearly.

Abstract: Parameters of processing (heat treatment temperature, holding time) and properties (Bending strength and Microhardness) of Ti₂AlC/TiAl compound materials were obtained through mechanical properties examination, the network model was built by BP artificial neural network. The results show that the built model can reflect the relationships between processing and properties very well and has certain accuracy. It can be used for the prediction of the properties of Ti₂AlC/TiAl compound materials after heating processing under different experiment conditions. Meanwhile, the model can also serve as a guide for the preparation technology of Ti₂AlC/TiAl compound materials.