Study on the milling processes and sintering properties of Ag/SnO2 electrical contact material with different micro-structured SnO2 powders

• Published in: Journal of sol-gel science and technology 2023-05, Vol.106 (2), p.444-454
• Main Authors: Zhang, Ji, Mu, Chengfa, Shen, Tao, Qi, Gengxin
• Format: Article
• Language: English
• Subjects: Activation energy; Atmospheric models; Ceramics; Chemical synthesis; Chemistry and Materials Science; Circuits; colloids; Composites; Densification; Electric contacts; etc.; fibers; Finite element method; Glass; Inorganic Chemistry; Materials Science; Microspheres; Nanotechnology; Natural Materials; Nucleation; Optical and Electronic Materials; Original Paper: Nano-structured materials (particles; Physical properties; Process parameters; Sintering; Sintering (powder metallurgy); Sol-Gel Research in China; Specific gravity; Spherical powders; Tin dioxide
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-022-05930-w

Different micro-structured SnO 2 powders were synthesized by hydrothermal and chemical co-precipitation methods. The influence of milling process and sintering parameters on the physical properties of Ag/SnO 2 electrical contact materials was investigated. The microstructure and physical properties of Ag/SnO 2 electrical contact materials were characterized by X-ray Diffraction, Scanning Electron Microscopy and Conductivity analyzer. The results showed that spherical SnO 2 (s) powders with a diameter about 2 μm were synthesized. With increased milling time, there was a slight decrease in the average sizes of Ag/SnO 2 (s) powders, but no significant difference. The optimal density of 9.545 g∙cm −3 and resistivity of 2.67 μΩ∙cm of Ag/SnO 2 (s) electrical contact materials were obtained after sintering at 860 °C for 6 h in air atmosphere. The promotion of sintering densification and improvement of physical properties of Ag/SnO 2 (s) contact may be due to the combined effects of mechanical activation energy and higher sintering temperature. Using the finite element method, simulation models were developed to interpret the effects of different micro-structured SnO 2 powders on the physical properties of Ag/SnO 2 materials. Graphical abstract Highlights Mechanism on nucleation and growth behavior of SnO 2 microspheres has been proposed. Due to the combined effects of mechanical activation energy and high sintering temperature, the sintering densification behavior and conductivity properties of Ag/SnO 2 (s) contact were improved. The conductivity mechanism was explained by quantitative analysis of the relative density ( γ ) and porosity ( θ ) of Ag/SnO 2 contacts, and a standard electrical circuit model has been applied.