机械合金化法制备AgCr触头材料及其性能研究

发布时间：2018-06-06 16:57

本文选题：电触头材料 + 机械合金化　；参考：《暨南大学》2010年硕士论文

【摘要】： 电触头主要负责接通、断开电路及负载电流的任务,由于它的特殊作用,电接触材料的性能直接影响电子产品的可靠性、稳定性、精度和使用寿命。在闭合和断开的过程中触头受到电侵蚀是导致其不能正常工作的主要原因。因此开展抗电侵蚀性能强的电接触材料的研究有重要的意义。本文主要研究机械合金化法制备AgCr触头材料及其性能。首先,分析球磨转速和球磨时间对球磨粉末物相、晶粒大小、微观应变和粉末形貌的影响,主要是用X射线衍射仪和扫描电子显微镜对粉末进行物相及形貌分析。其次,研究球磨转速、球磨时间、球料比和烧结温度等工艺参数对AgCr合金材料的密度、硬度、导电性、金相结构的影响,总结出制备性能优异的AgCr合金材料的工艺。最后,通过对电路电流及通断比的变化、触头接触电阻的变化和接触表面形貌及成分的分析研究,可综合分析触头材料的电接触性能。通过比较AgCr触头、铜基覆银触头、AgSnO2触头在电流作用下的接触性能,检验AgCr触头是否具有较强的抗电侵蚀能力。研究结果表明：当球磨转速达到一定值,球磨到一定时间,Cr相能部分固溶到Ag相中。适当的球磨工艺参数和烧结温度可以制备出性能相对优异的AgCr合金,其制备的AgCr(Cr含量12 wt%),密度为9.62 g／cm3,硬度为122.3 HV,导电率4.03μΩ·cm,同时烧结体金相结构表明该工艺参数下制备的触头材料组织分散较均匀,无明显团聚现象,具有很好的开发和应用前景。 AgCr触头电接触性能分析表明：分别在相同测试条件下,发现AgCr触头电性能要优于铜基覆银触头；而与AgSnO2触头相比,AgCr对称触头材料转移量更大,但是AgSnO2触头接触表面有裂纹生成,并且闭合分断电流达10万次后,AgCr对称触头保持接触电阻低而稳定,同时电路通断比没变化。总体评价：AgCr触头具有较好的电接触性能。
[Abstract]:The electrical contact is mainly responsible for the task of turning on, disconnecting circuit and load current. Because of its special function, the performance of electrical contact material directly affects the reliability, stability, precision and service life of electronic products. Electrical erosion of the contact during closure and disconnection is the main cause of its failure to work properly. Therefore, it is of great significance to study the electrical contact materials with strong resistance to electrical erosion. In this paper, the preparation and properties of AgCr contact materials by mechanical alloying are studied. Firstly, the effects of ball milling speed and milling time on the phase, grain size, micro strain and powder morphology of ball milling powder were analyzed. The phase and morphology of the powder were analyzed by X-ray diffractometer and scanning electron microscope. Secondly, the effects of milling speed, milling time, ratio of ball to material and sintering temperature on the density, hardness, electrical conductivity and metallographic structure of AgCr alloy were studied, and the process of preparing AgCr alloy with excellent properties was summarized. Finally, the electrical contact properties of the contact materials can be comprehensively analyzed by analyzing the changes of the circuit current, the on-off ratio, the contact resistance, the morphology and the composition of the contact surface. By comparing the contact properties of AgCr contacts and copper based silver coated contacts with AgSnO2 contacts under the action of electric current, the results show that the AgCr contacts have strong resistance to electric erosion. The results show that when the ball milling speed reaches a certain value, The Cr phase energy is partially dissolved into Ag phase by ball milling to a certain time. AgCr alloys with relatively excellent properties can be prepared by proper ball milling process parameters and sintering temperature. The AgCr-Cr content is 12 wtlong, the density is 9.62 g / cm ~ 3, the hardness is 122.3 HVand the conductivity is 4.03 渭惟路cm. At the same time, the microstructure of the sintered contact material is uniform and there is no obvious agglomeration. The analysis of the electrical contact properties of AgCr contacts shows that the electrical properties of AgCr contacts are superior to those of copper based silver contacts under the same test conditions, and the amount of material transfer of AgCr symmetrical contacts is larger than that of AgSnO2 contacts. However, there are cracks on the contact surface of AgSnO2 contacts, and the AgCr symmetrical contacts keep the contact resistance low and stable after the closing breaking current reaches 100000 times, while the on-to-break ratio of the circuit does not change. The general evaluation shows that: AgCr contacts have better electrical contact performance.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：TM24

【参考文献】