Sintering characteristics of nickel and tin metal powder

Apr 25 08:13 2012 David Yvon Print This Article

In recent years, powder metallurgy technology has become the world's fastest growing metal forming technology. Ni-Sn alloy has been widely applied to modern industrial production.

Because of its black appearance,Guest Posting Ni-Sn platings is often used as a coating for gun color or black pearl plating. Sintering properties of the nickel-tin powder alloy is researched though the powder permeation method. By changing the sintering temperature and holding time, the suitable temperature pressure and sintering process parameters forming nickel-tin intermetallic compounds can be got. It provides reference material for the production of powder metallurgy products.

Finished nickel powder, tin powder, powder particle size of 47 ~ 61 ptrn purity of the chemical analytical grade. The sample preparation process: the nickel and tin metal powder in a 1:1 ratio preparation; dried and weighed in proportion to the particle size in the 47 to 61 um metal powder, a mixture of hand-grinding in the grinder 30min, so mixed thoroughly; WE a 30B hydraulic universal testing machine, pre-pressure (100 kN) forming a barrel-type holding furnace at 100 ° C insulation for 0.5 h, and then hot pressing (300 kN) forming, so that preparation of a test need the green body. To suppress a good specimen shown in the table below the sintering temperature and holding time into SX2l0.12 box-type resistance furnace sintering.

When the holding time at the same time, as the sintering temperature, the microhardness on the rise. Sintering temperature under the same conditions, with the holding time, the microhardness showed a small increase in trend. Under the same sintering temperature, holding time, atomic diffusion, is more conducive to full contact with the reaction occurs in the particles, lower porosity, the alloy has become relatively dense, density tended to increase, making it an increase in microhardness. With the sintering temperature increased, the atomic motion is increased, the diffusion coefficient increases rapidly, greatly increased the rate of silicon powder diffusion and diffusion extent, is more conducive to the spread, between the different particles into each other's gaps, and gaps in the matrix gradually decreases, as a whole has become more dense, microhardness showed a significant increase in trend.

Nickel powder and tin powder is mixed repress and sintered at 100 ° C. In 5h insulation process conditions, the main intermetallic compounds are Ni of Sn2, Ni Sn, Ni.Sn4 and NiSn. In the insulation of 15 h, the microhardness of nickel-tin intermetallic compounds increase with the sintering temperature increasing. The variation of density is like the microhardness. With the holding time under the same sintering temperature, the hardness and density of nickel-tin intermetallic compounds were tested in increasing trend. Unsintered samples have rarely nickel-tin diffusion with no new phases. For the sintered samples, there are irregular goose egg-shaped cell in nickel powder and tin powder. There is a full proliferation response and it generates a new phase of nickel tin intermetallic compounds. As the sintering temperature increased, within a certain range it helps to achieve the desired tissue, and the grains gradually grow. But the too high temperature is not conducive to acquisition of the compounds organizations.Source:

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