Silver-boron nitride-cerium switch apparatus contact material and preparation method thereof

Abstract

The invention discloses a silver-ceramic series electric contact material and a preparation method thereof. The material consists of 1 to 15 weight percent of boron nitride (BN), 0.5 weight percent of cerium (Ce) and the balance of silver (Ag). The silver-boron nitride-cerium contact material prepared by the method is second-phase boron nitride (BN) particles which are dispersed and distributed in a silver matrix to reinforce the contact material, and the addition of the cerium improves wettability of liquid-state silver on the boron nitride to prevent the second-phase particles from clustering and more compactly combine the silver with the boron nitride. Experimental results of electric life after 2 hundred thousand times of action at direct current of 12V and lamp load of 8*21W+5*5W (impact current of 33A and steady current of 16A) can show that the pitting of a contact is not serious, and the contact material is not obviously transferred and the material has the advantages of high arc erosion resistance, material transfer resistance and comprehensive performance.

Description

technical field [0001] The invention relates to a silver-ceramic electrical contact material and a preparation method thereof, in particular to a silver-boron nitride-cerium switch electrical contact material with excellent comprehensive performance of arc ablation resistance, material transfer resistance and excellent comprehensive performance and its preparation method. Background technique [0002] Electrical contacts are the components in switching appliances that are directly responsible for making and breaking circuits, and play a decisive role in the safe operation of switching appliances. With the development of low-voltage electrical appliances such as relays and contactors in the direction of high power, miniaturization and high reliability, higher performance requirements are also put forward for the supporting contact materials: (1) Good electrical conductivity and thermal conductivity ; (2) Resistance to electrical wear; (3) Strong resistance to fusion welding;...

AI Technical Summary

Problems solved by technology

However, in the actual development and application, it is found that the above-mentioned contact materials have common deficiencies: (1) Under the repeated action of the arc, SnO 2 Concentration of components on the surface of the contact leads to an increase in contact resistance and a higher temperature rise

Both processes have their own advantages and disadvantages: 1) The material prepared by the internal oxidation process has a fine grain structure, but an uneven microstructure along the radial direction of the sample exists, and there is a barren area; there are oxides precipitated at the grain boundary, and its electrical conductivity is low ( It is only half of the conventional material); on the surface of the material, it is also easy to crack and be destroyed along the particle boundary

Due to the unreasonable microstructure of the material, the performance of electrical appliances is poor

2) The powder metallurgy process is not limited by the composition of the components, and the prepared material is evenly dispersed, avoiding the barren area, and the structure is uniform; the preparation process is simple, but the contact density is lower than that of the internal oxidation process, the hardness is lower, and the arc corrosion resistance is poor. Some; the processing technology is complicated, the processing is difficult, the yield is low, the cost is high, and it is not easy to make products such as rivets or sheets that require large deformation

Western European countries tend to use powder metallurgy, and Japan mainly uses internal oxidation, but in recent years, it has also actively developed powder metallurgy products. The problem of price and cost limits the development of internal oxidation manufacturing process

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