Phase-field simulation of secondary dendrite growth in directional solidification of binary alloys

• Published in: China foundry Vol. 16; no. 2; pp. 97 - 104
• Main Authors: Feng, Li, Lu, Ni-ni, Gao, Ya-long, Zhu, Chang-sheng, Zhong, Jun-he, Xiao, Rong-zhen
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.03.2019; Foundry Journal Agency; College of Materials and Engineering, Lanzhou University of Technology, Lanzhou 730050, China; State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050,China%College of Materials and Engineering, Lanzhou University of Technology, Lanzhou 730050, China%State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050,China
• Subjects: Alloys; binary alloy; Crystal structure; directional solidification; Engineering; Grain boundaries; Machines; Manufacturing; Materials Engineering; Metallic Materials; phase-field method; Processes; Research & Development; secondary dendrites; Specialty metals industry; China; A; TP391.9; binary alloy; phase-field method; directional solidification; secondary dendrites
• ISSN: 1672-6421; 2365-9459; 1672-6421
• DOI: 10.1007/s41230-019-8126-6

Phase field method was used to simulate the effect of grains orientation angle θ 11 and azimuth θ A of non-preferentially growing dendrites on the secondary dendrites of preferentially growing dendrites. In the simulation process, two single-factor influence experiments were designed for columnar crystal structures. The simulation results showed that, when θ 11 < 45° and θ A < 45°, as θ 11 was enlarged, the growth direction of the secondary dendrites on the preferentially growing dendrites at the converging grain boundary (GB) presented an increasing inclination to that of preferentially growing dendrites; with increasing θ A , the growth direction of the secondary dendrites on the preferentially growing dendrites at the converging GB exhibited greater deflection, and the secondary dendrites grew with branches; the secondary dendrites on the preferentially growing dendrites at diverging GBs grew along a direction vertical to the growth direction of the preferentially growing dendrites. When θ A = 45° and θ 11 = 45°, the secondary dendrites grew in a direction vertical to the growth direction of preferentially growing dendrites. The morphologies of the dendrites obtained through simulation can also be found in metallographs of practical solidification experiments. This implies that the effect of a grain’s orientation angle and azimuth of non-preferentially growing dendrites on the secondary dendrites of preferentially growing dendrites does exist and frequently appears in the practical solidification process.