Two-dimensional phase-field simulations of competitive dendritic growth during laser welding. (5th November 2019)

• Record Type: Journal Article
• Authors: Gaoyang, Mi; Lingda, Xiong; Chunming, Wang; Ping, Jiang; Guoli, Zhu
• Is Part Of: Materials & design. Volume 181(2019)
• Publication Date: 2019-11-05
• Subjects: Phase-field model -- Competitive dendritic growth -- Laser welding -- Al-Cu alloy -- Crystalline orientation -- Grain boundary; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2019.107980
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: A phase-field model is applied to study competitive dendritic growth between different grains with different crystalline orientations during laser welding of Al-Cu alloy. An unfavorable oriented (UO) grain is set to locate between two favorable oriented (FO) grains to study the dendritic growth behaviors at not only converging grain boundary (GB) but also diverging GB. It is found that the cellular dendrites appear firstly nearby the GBs at initial instability stage. At early competitive growth stage, the UO misalignment angle influences the competitive dendritic growth at both GBs. After completely entering competitive growth stage, the leading dendrites that are much faster than other dendrites at GBs firstly grow in lateral direction. The side branches growing from leading dendrites block growth path of nearby dendrites and change the UO/FO grain widths. The converging GB deflection angle and the side branch development at diverging GB as characteristic competitive dendritic growth behavior at relatively steady growth stage also significantly affect UO and FO grain widths. The numerical results are basically consistent with microstructure obtained by experiment. Graphical abstract: Unlabelled Image Highlights: Competitive growth of dendrites with different crystalline orientations is studied. The cellular dendrites first appear from planar interface nearby grain boundaries. Dendrites with small inclined angle can overgrow dendrites with 0 0 inclined angle. Lateral dendritic growth, grain boundary angle and side branch affect grain width.