Ping LI
,
Kemin XUE
,
Yan LU
,
Jianrong TAN
材料科学技术（英）
Ti-15-3 alloy is a new metastable β- type titanium. The influence of hot deformation parameters on the microstructure of Ti-15-3 alloy after solution treatment has been studied by isothermal compression tests as well as quantitative metallographic analysis. On the basis of the data obtained from the tests, predicting models for equivalent grain size and recrystallization volume fraction have been established with an artificial neural network method. An FE numerical simulation system has been developed to simulate the distribution of microstructure in Ti-15-3 alloy after hot back extrusion and solution treatment by combining the neural network model with thermal-mechanical coupled rigid-viscoplastic FE model. Corresponding experimental research is performed. The agreement of the simulated results with measured ones shows that the simulation system is reliable.
关键词:
Ti-15-3 alloy
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Ping LI
,
Qing ZHANG
,
Kemin XUE
材料科学技术（英）
Grain shape of the hot deforming alloy is an important index to character the microstructure and performance of material. The fractal theory was applied to analyze the recrystallized microstructure of Ti-15-3 alloy after hot deformation and solution treatment. The fractal dimensions of recrystallized grains were calculated by slit island method. The influence of processing parameters on fractal dimension and grain size was studied. It has been shown that the shapes of recrystallized grain boundaries are self-similar, and the fractal dimension varies from 1 to 2. With increasing deformation degree and strain rate or decreasing deformation temperature, the fractal dimension of grain boundaries increased and the grain size decreased. So the fractal dimension could characterize the grain shape and size. A neural network model was trained to predict the fractal dimension of recrystallized microstructure and the result is in excellent agreement with the experimental data.
关键词:
Ti-15-3 alloy
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