Microstructure and Hardness Property of Internally Oxided AgCdO Alloy

Lee, Hyo Soo; Shin, Hyung Won; Jung, Taek Kyun; Kim, Tae‐Bum; Lee, Min Ha

doi:10.4028/www.scientific.net/amm.152-154.440

Cited by 4 publications

(3 citation statements)

References 11 publications

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“…AgCdO releases toxic Cd vapor during use. The European Union issued RoHS and WEEE directives to limit the use of cadmium and other harmful substances in electronic and electrical equipment [ 4 , 5 ]. AgSnO 2 is non-toxic, environmentally friendly and has excellent performance, and is fast becoming the most promising contact material to replace AgCdO.…”

Section: Introductionmentioning

confidence: 99%

Properties of AgSnO2 Contact Materials Doped with Different Concentrations of Cr

Wang

Zhu

et al. 2022

Materials

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As an important component carrying the core function and service life of switching appliances, the selection and improvement of electrical contact materials is of great significance. AgSnO2, which is non-toxic, environmentally friendly and has excellent performance, has become the most promising contact material to replace AgCdO. However, it has deficiencies in machinability and electrical conductivity. The property of AgSnO2 contact material was improved by doping element Cr. The relationship between the mechanical and electrical properties of AgSnO2 contact materials and doping concentrations were investigated and analyzed by simulation and experiment. Based on the first principle, the elastic constants of supercell models Sn1−xCrxO2 (x = 0, 0.083, 0.125, 0.167, 0.25) were calculated. The results show that the material with a doping ratio of 25% is least prone to warp and crack, and the material with a doping ratio of 12.5% has the best toughness and ductility and the lowest hardness, which leads to molding and is subsequently easier to process. The Cr-doped AgSnO2 contacts with different doping proportions were prepared by the sol–gel and powder metallurgy method. Additionally, their physical performance and electrical contact properties were measured in experiments. The results show that the doped SnO2 powders prepared by the sol–gel method realize integration doping, which is consistent with the crystal model constructed in the simulation calculation. Sn0.875Cr0.125O2 has lower hardness, which is beneficial to process and form. Doping helps to stabilize the arc root, inhibit the ablation of contact by arc, reduces arc duration and arc energy, improves the resistance to arc erosion of AgSnO2 contact material, and makes electrical contact performance more stable. The contact material with a doping concentration of 16.7% has the best arc erosion resistance.

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Section: Introductionmentioning

confidence: 99%

Properties of AgSnO2 Contact Materials Doped with Different Concentrations of Cr

Wang

Zhu

et al. 2022

Materials

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“…Although, the annex to the RoHS Directive exempts the use of Cd and its compounds in electrical contacts. However, in 2019, the EU further revised the RoHS Directive, stipulating that the use of Cd and its compounds in electrical contacts can be exempted until 21 July 2021 for most applications, and a small number of special applications can be exempted until at the latest 21 July 2024 [ 3 , 4 ]. Therefore, the research for environmentally friendly electrical contact materials to replace Ag/CdO has attracted extensive attention.…”

Section: Introductionmentioning

confidence: 99%

Study on Simulation and Experiment of Cu, C-Doped Ag/Ni Contact Materials

et al. 2022

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Ag/Ni contact material with greenery and good performance is a cadmium-free silver-based contact material that has been vigorously developed in recent years. However, Ag/Ni contact material has poor welding resistance. Based on the first principles of density functional theory, the interface model of Cu, C-doped Ag/Ni was established. The work of separation and interfacial energy of interface models showed that doping can improve the interfacial bonding strength and interfacial stability, with C-doped Ag/Ni having the strongest stability and interfacial bonding strength. It can be seen from the population and density of state that covalent bonds exist between Ag and Ni atoms of the Ag/Ni phase interface at the electronic structure level. Finally, the doped Ag/Ni contact material was prepared by the powder metallurgy method. Through the arc energy and welding force in the electrical contact experiment, it was obtained that the welding resistance of C-doped Ag/Ni was better than Cu-doped Ag/Ni contact material, which verified the correctness of the simulation results. Overall, the present study provides a theoretical method for the screening of doping elements to improve the performance of Ag/Ni contact material.

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“…According to the revised directive, it is clear that Cd and its compounds in electrical contacts are exempted in most applications until July 21, 2021, a few special applications can be exempted to the latest on July 21, 2024 [3], [4]. Due to the requirements of environmental protection, and AgCdO materials are increasingly difficult to meet the performance of electrical switches for contact materials such as high reliability and long life [5]. It is urgent for us to find a new contact material to replace AgCdO.…”

Section: Introductionmentioning

confidence: 99%

Research on Simulation, Experiment and Evaluation Method of Different Ratio Gd Doped AgSnO₂ Contact Material

et al. 2020

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AgSnO 2 electrical contact material with greenery and good performance has the most potential to replace the toxic AgCdO. However, SnO 2 in AgSnO 2 contact material is a kind of semiconductor with wide band gap, which is almost insulated and has high hardness, resulting in the increase of contact resistance and temperature rise, and easy to form microcracks. First principle based on density functional theory are used to simulate three doping ratios (8.3%, 12.5%, 16.7%) of rare earth element Gd doped SnO 2. The simulation results show that when the doping ratio is 12.5%, electrical performance is the best. As the doping ratio increases, the smaller the hardness, the higher the probability of microcracks. To more objectively obtain the doping ratio with the best comprehensive performance, the comprehensive evaluation model of Technique for Order Preference by Similarity to Ideal Solution with entropy weight is adopted to evaluate, and the performance with doping ratio of 12.5% is the best. Finally, it is verified by experiments. Different ratio of Gd doped SnO 2 powders are prepared by the sol-gel method, and the X-ray diffraction test proves that the sol-gel method can realize the substitution doped model established by simulation. The doped AgSnO 2 is prepared by powder metallurgy method, and its electrical performance and hardness are measured. The theory and experiment can be well matched, which proves the feasibility and credibility of simulation. It provides a new idea and scientific reference for the research on doping to improve the properties of AgSnO 2 contact material. INDEX TERMS AgSnO 2 contact material, doping, first principle, comprehensive evaluation method.

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Microstructure and Hardness Property of Internally Oxided AgCdO Alloy

Cited by 4 publications

References 11 publications

Properties of AgSnO2 Contact Materials Doped with Different Concentrations of Cr

Properties of AgSnO2 Contact Materials Doped with Different Concentrations of Cr

Study on Simulation and Experiment of Cu, C-Doped Ag/Ni Contact Materials

Research on Simulation, Experiment and Evaluation Method of Different Ratio Gd Doped AgSnO₂ Contact Material

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