Study On The Fretting Characteristics And Environmental Characteristics Of Contact Pairs Of The Same Material

Connector is a very important component to achieve stable signal transmission.There are many factors affecting its reliability,the most important of which is fretting and environmental factors.In this paper,the contact pairs of the same materials consisting of six different coated metals are taken as the research object.The three evaluation indexes are the final contact resistance,the number of cycles used when the contact resistance reaches 500m?,and the number of cycles used when the resistance rises to the maximum.Orthogonal experiments are designed to explore the fretting characteristics.The temperature and humidity cycling experiments and salt spray experiments were carried out on the fretting samples to explore the influence of environment on Fretting characteristics.The final fretting characteristics of combination 1 Au0.76?m(BeCu)-Au(Cu),combination 2 Ag4?m(BeCu)-Ag(Cu)and combination 3 Sn4?m(BeCu)-Sn(Cu)based on Cu are:combination 2>combination 1>combination 3.When the final contact resistance is used as the evaluation index,the material is the most important factor affecting the fretting characteristics,followed by temperature,pressure and coating thickness.When the contact resistance reaches 500m?,and the period from resistance rise to maximum is taken as the evaluation index,the material is still the most important influencing factor.Temperature,pressure and coating thickness are not primary or secondary.The optimum level of material is combination 2.The order of temperature and humidity environmental characteristics of contact pairs from good to bad is combination 3>combination 2>combination 1.The order of the environmental characteristics of salt fog resistance of contact pairs from good to bad is combination 2>combination 3>combination 1.When the substrate is C18070,combination 4 Au0.76?m(C18070)-Au(Cu),combination 5 Ag4?m(C18070)-Ag(Cu),combination 6 Sn4?m(C18070)-Sn(Cu)have the final fretting characteristics,combination 4>combination 5>combination 6.When the final contact resistance is taken as the evaluation index,the best coating material is the gold-plated contact pair.When the contact resistance reaches 500mn,the number of cycles used to rise from resistance to the maximum value is taken as the evaluation index,the most important influencing factors are the coating material,temperature,contact pressure and coating thickness,and there is no primary or secondary difference.Combination 5 is better than combination 6 and better than combination 4.The optimal temperature and contact pressure of all combinations are 25?,300g and the optimal coating thickness is medium(0.76?m for gold plating,4?m for silver plating and tin plating).Combination 5 is better than combination 4 and better than combination 6.