Initial-Stage Sintering of the Active BeO Powder

Initial-stage sintering of the active BeO powder was investigated by measuring the isothermal shrinkage of its powder compacts continuously with a thermo-dilatometer consisting of a linear variable differential transformer activating an X-Y recorder, in vacuum for the temperature range 1250° to 1450°C.The results obtained were summarized as follows:(1) Initial-stage sintering of the active BeO powder was found to be a rapid densification process represented by the straight line with a slope of unity, when logarithm shrinkage was plotted against logarithm time.(2) Large amounts of the initial shrinkage for a short time period due to this process markedly shortened the time to complete the densification. The phenomenon showed characteristically one of many properties of the active BeO powder, which is considered to be sinterable.(3) This process was followed by the neck growth due to vacancy-volume diffusion.