Study Of Hollow Cathode Dischage Using In Speedy High Temperature Sintering Process

Powder Metallurgy is a very important branch of metallurgy. And the sinteringprocess always plays a key role which can affect the quality of the powder metallurgyproduct. Since we've step into the new century, the modern industry have got a bigdevelopment with the naissance of new technology. And the powder products countmore among the industry products. It puts forward the higher request about theproperty and the quality of the powder product. In this paper, it is discussed that theHollow Cathode Discharge can be used as a method in speedy and high temperaturesintering process which can be applied in high melting point metal and ceramicmaterial. And the saturating metal technics can be also added in the process. It willenrich the technique of iron powder sintering. In this paper, it is started from the discharging discipline of the Hollow CathodeDischarge. The lit condition, discharging current, and the rising temperature propertyare also discussed. It is followed that the pressure and the voltage influence thecurrent density and the temperature. The result shows that the basic lit condition is theoverlap of negative glow. The current can be amplified through the oscillation ofelecttrons. With the comparison of cylinder-shaped HCD and parallel plank HCD, thelatter can provide more powerful current under the same condition of voltage andpressure. And it can accelerate the rising of temperature which can be applied in thehigh temperature engineering area. With the sintering experiment of different additives AlN ceramic, it is discussedin this paper that the appropriate parameters can be very helpful in makinghigh-powered AlN ceramic. The result shows that with the adjustment of the sinteringparameters such as voltage and pressure, the output power can be well controlled. Andthe fast sintering can be achieved with the high density plasma. In short time, thesample can get compactness. According to the experiment, the relative density of theAlN sample can be 98.88％ and thermal conductive rate of the AlN sample canreach 93.8W/mK under the conditions of 5.5wt% Y2O3－CaO－Li2O addictive;1700℃;and 3 hours'holding time. In the experiment of sintering iron powder, alloying metal process is added. Themicrostructure can clearly indicate the steps of the samples' densification process II摘 要during different parameters.The result shows that with the adjustment of the HCDparameters, iron powder can be sintered closely. And the integrate alloying layer canbe formed on the surface as well.