Connection of CuW alloy with CuCrZr alloy
Electric contact is the contact element of electric switch, which is mainly responsible for breaking the load current. The contact and arc extinguishing system are the core of the switch and play a vital role in circuit protection. The safety, reliability and breaking characteristics of switches are largely determined by the physical properties of the contact material. Most of the existing electric contacts are integral CuW/CuCr contacts. However, with the increase of power grid capacity, the heat generated when the contact is broken increases sharply, and the high temperature performance of the CuCr alloy on the integral CuW/CuCr contact is also put forward more and more stringent requirements. CuCrZr alloy has become the material of choice for the conductive section of the next generation integral contact due to its superior high temperature performance. However, Zr has a strong affinity for oxygen, and the CuW/CuCrZr interface is prone to generate ZrO2 inclusions during the bonding process, resulting in low bonding strength.
A certain amount of tungsten powder is cold-pressed into billet and sintered at high temperature. The sintered tungsten block is obtained by holding heat and cooling in the furnace. A certain amount of CuCrZr alloy block is placed above the sintered tungsten block and then placed in the vacuum furnace for melting and cooling after holding heat, and the molten CuW alloy is obtained. Division I can produce and process tungsten block according to customer's requirements. The chemical composition of tungsten block, the mechanical properties of tungsten block can meet customer requirements.
The connecting surface of CuW and CuCrZr alloy was processed and cleaned. The CuW alloy was placed on top of CuCrZr alloy and placed in a crucible in an atmosphere vacuum sintering furnace. The CuW alloy was connected with CuCrZr alloy by two-step sintering method, and the CuW/CuCrZr alloy block was obtained.
After solution and aging treatment, the CuW/CuCrZr alloy was prepared.
