From the Eighties, China has commenced to explore the usage of plasma spheroidized tungsten powder, but there has been a slight oxidation phenomena at the spherical tungsten powder floor, so that it will put together natural spherical tungsten powder, it also need to retumbo powder for sale behavior hydrogen discount at the spheroidization processed powder, in order that the production performance is low, fee greater, difficult to acquire the necessities of commercial manufacturing.
Recently, scientists have advanced the first plasma powder processing system in China, the system makes use of a water-cooled quartz plasma torch substantially lessen the quantity of inert cooling gas, successfully keep away from the oxidation of tungsten steel powder in spheroidization system. Use irregular shape tungsten powder as the uncooked fabric, the particle length in the variety of 5.Five ~ 26.5¼m, thru plasma nodulizing managing to gain a clean floor, appropriate sphericity powder, its spheroidization charge reached one hundred%, and stays single phase tungsten powder after spheroidizing.
The bulk density of 26.5¼m particle size tungsten powder after spheroidizing turned into improved from 6.80g/cm3 to 11.5g/cm3, the powder liquidity also stepped forward markedly. The research display that any such radio-frequency plasma processing approach can organized micron single segment round tungsten powder, does not exist powder oxidation trouble, high manufacturing efficiency, low fee, suitable for industrialized manufacturing requirements. They additionally studied the affect of system parameters to tungsten powder spheroidized, observed the affordable feed price is an crucial aspect to make certain the powder spheroidization fee. Excessive feed charge can’t satisfy the want of tungsten powder take in warmth, melting and spheroidizing, also cause a part of the powder inside the plasma walking tune deviate the plasma excessive-temperature area, make the powder soaking up not enough warmness, ensuing the processed powder reduce spheroidization price. In addition, whilst the feeding charge is steady, the spheroidization charge decreased with the preliminary powder particle size elevated. The smaller the preliminary powder particle length, the bigger the unique surface area, while the plasma take in extra energy in the crossing, it will more conducive to powder spheroidization. Generally, as powder particle size reduced, the melting point reduced, absorb the same quantity of power is easier to spheroidizing. Therefore, under the equal method parameters, smaller particle size of the powder with higher spheroidization charge.
Use RF plasma spheroidizing different metals such as non-ferrous metallic powder. RF induction thermal plasma prepared submicron copper powder, when copper powder thru plasma, appears gasification, nucleation, condensation. However, the low melting point metal in the plasma sphere manner unavoidably arise evaporation and gasification, the organized steel powder encompass a lot of fine spherical powder acquired by way of evaporation, coagulation, particle length variety of the product distribution is broader. This is a problem to be solved.