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Zirconia Smelting Matters

Hangzhou JWG Technology Co.Ltd | Updated: Sep 20, 2017

Zirconia ceramic rod hot pressure sintering is a one-way pressure sintering method, its principle is very simple. The definition of hot-pressing sintering is to fill in the dry powder into the model, and then heat it from the side of the uniaxial direction to make the molding and sintering simultaneously a sintering method. The process of hot-pressing sintering is simply the dry pressure forming at high temperature, which means that the mould and product can be heated at the same time, and pressure is applied, so the powder is not to be formed when sintered.

Zirconia ceramic rod hot pressing sintering process

The heating method in hot-pressed sintering is still the electric heating method and the pressure method is the oil pressure method. The mould can be used in the graphite mould or alumina ceramic mould according to different requirements. Normally used graphite molds must be used in non-oxidizing atmospheres, with a pressure of 70MPa. Graphite mould is easy to make and low cost. The aluminum oxide mould can reach 200MPa, suitable for oxidizing atmosphere, but difficult to make, high cost and low life.

Hot-pressing sintering characteristics: hot pressing sintering pressure due to heating simultaneously, thermoplastic powder, help contact, flow and mass transfer process of particle dispersion, thus forming pressure is only 1/10 of the cold press; It can also reduce the sintering temperature, shorten the sintering time, thus resist the grain growth, and get the products with fine grain, high density and good mechanical and electrical properties. It can produce ultra-high purity ceramic products without adding sinter or molding auxiliaries. The disadvantage of hot-pressing sintering is that the process and equipment are complex, the production control requirements are strict, the mold material requirements are high, the energy consumption is large, the production efficiency is low, the production cost is high.

Smelting of zirconia ceramic structures

The smelting of zirconia ceramic structures is a lot of steps, so we need special attention every step of the way to ensure the quality is too strong.

No matter use, intermediate frequency furnace or electric arc furnace smelting, always smelting carbon steel, and all kinds of ferromanganese and other precious alloy material, to several times, each time a small amount of charging, valuable elements in the last, in order to reduce loss. The block should be as small as possible, with 50-80mm as appropriate.

Rongqing, the temperature reaches 1580-1600 ℃, deoxidization, dehydrogenation and denitrification, aluminium wire are available, and also can use Si - Ca alloy or SiC materials. Press the deoxidizer to the bottom of the furnace. The metal liquid is covered with a covering agent and the outside air is broken. Keep calm for a while, so that the oxide and inclusions have plenty of time to float.

Ahead of the ladle baking to more than 400 ℃ is very necessary. Zirconia ceramic structure during out with V - Fe, Ti, Fe do modification treatment, rare earth and other trace elements, is the necessary means to refine a crystallization, its impact on the zirconia ceramic structure performance is critical.

Hangzhou JWG Technology Co.Ltd