Sintering of aluminium alloy powders using pulse electric current sintering process

摘要

The pulse electric-current sintering process is the methodnas shown in Figure 1: Powders are filled in a carbonmadensintering die and sintered by applying pulse-statenvoltage directly, supplying electric current to heat whilenpressurising with a carbon-made punch.nHistorically, this process has evolved as PAS (PlasmanActivated Sintering) and SPS (Spark Plasma Sintering.nNowadays, devices for this process are called SPSn“Plasma discharge sintering device” and more than 300nof them have been introduced to educational institutions,npublic research centres and private companies in andnoutside Japan1. Recently, the device called Plasman isnalso commercially available2. Although their names arendifferent by distributor, they are fundamentally devicesnlike the one shown in Figure 1, which perform sinteringnand bonding in the vacuum chamber by supplying thenelectric current.nDevices can be divided roughly into two groups bynthe waveform of the current supplied: One, the devicesnwhich apply the same rectangular waveform as that ofnthe electric discharge machine and of the power usednfor TIG welding, and the other, the devices whichnapply rectified waveform of alternating current. Thenprocess is sometimes called by the above mentionednproduct name but recently it is also often called thenpulse electric-current sintering Process. There are alsondevices characterised by the pressure direction and thenapplication of minute pressure during heating3, as wellnas devices with newly designed methods for the electricnresistance and the heat insulation of the carbon die sonas to conduct heating efficiently.