Temperature Gradient Field Theory of Nucleation

2nd International Manufacturing Engineering Conference; 3rd Asia-Pacific Conference on Manufacturing Systems

Das, S.^1 ; Ain, W.Q.^2 ; Azhari, A.^2 ; Rao, A.K. Prasada^2

Department of Metallurgical and Materials Engg., National Institute of Technology, Raipur, India^1

Faculty of Manufacturing Engineering, Universiti Malaysia Pahang, Malaysia^2

关键词: Ceramic particle;    Interstitials;    Liquid particle;    Low temperatures;    Metallic liquid;    Nucleation rate;    Nucleation temperature;    Temperature gradient fields;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/114/1/012099/pdf
DOI  :  10.1088/1757-899X/114/1/012099

来源: IOP

【 摘 要 】

According to the proposed theory, ceramic particles present in molten metal, lose heat at a slower rate than the metallic liquid during cooling. Such condition results in the formation of a spherical thermal gradient field (TGF) around each particle. Hence, the interstitials (low temperature) of such TGFs are the regions to reach the nucleation temperature first, owing to low energy barrier than the liquid-particle interface (higher temperature). Analytics also indicate that the nucleation rate is higher at the TGF interstitials, than at the liquid-particle interface. Such TGF network results in simultaneous nucleation throughout the system, resulting in grain refinement.