Rules Porous Copper-based New Self-lubricating Materials Preparation Technology And Its Dry Friction And Wear Properties

Solid-Gas eutectic undirectional solidification is a new kind of fabrication process of porous material.A special kind of porous material can made by this process whose pores distributed evenly and growed along with the direction of solidification The new porous material has not only traditional propertise such as light quality,good specific strength, high energy absorption but also has the special characteristics of itselfCu-Pb alloy is a common kind of solid lubricatting bearing material,which can be made traditionally by casting and powder metallurgy.Owing to the big difference between both sides of the density,there is a problem of gravity segregation in the course of fabrication.The impact toughness of sample which is made by powder metallurgy is poor. With the constant development of studies,new technologies are reported,for example a new kind of preparation technology was founded using magnetic field and casting to prevent gravity segregation in fabrication of Cu-Pb alloy.However,the energy consumption is too high,and the production process is too complex.In view of the characteristics above mentioned and the problems existing in the current preparation technologies. A new kind of self-lubricated composite material which is composed of ordered porous material copper made by Solid-Gas eutectic undirectional solidification and self-lubricated phase lead is introduced in this paper. The two parts of this new self-lubricated material are composited by the liquid metal alumetizing method. On one hand, the new self lubricating composite materials both has the lubrication function and some special related properties of ordered porous materials. On the other hand, this new Cu-Pb composite materials can avoid gravity segregation.Meanwhile,the preparation technology is so simple that the cost is low.The infiltration experiment shows that the major factors related the quality of new sample contans average pore size,temperature and infiltration,and the average pore size is most important.At the same time,this experiment also indicated that the method for fabrication of new Cu-Pb composite self-lubricating material is feasible. Dry friction and wear experiment surface that the new self-lubricating materials in this paper have good and strong ability to form a film self-lubricating.When the load beyond1MPa, the friction coefficient is less than0.08,and the friction coefficient have further reduced trend.with the increase of the load.The corresponding wear rate of quality is only about1/10～1/5of the casting Cu-30%Pb alloy under the same condition. The wear mechanism vary from abrasive wear to adhesive wear and plastic deformation with the increasing load.At the same time,the coefficient of friction decreaseed with the increasing sliding speed.Thus,the new material in this paper adapt to the condition with rapid speed and heavy load.