Analysis of Trace Amounts of Emitted Gases during Fracture of High-Purity Alumina under Ultrahigh Vacuum – Effects of Sintering Atmosphere and Sintering Time on Gas Emission Behavior-

摘要

The effects of sintering atmosphere and sinteringtime on gas emission behavior during fracture of high purityA1_2O_3 were investigated under ultrahigh vacuum using amass spectrometer to examine the behavior of gases in thematerial. The gas in the sintering atmosphere was predominantlyemitted at the moment of fracture for all specimens. The totalamount of gas emitted from a specimen sintered in O_2 was lessthan that of a specimen sintered in air or Ar, showing that themobility of O_2 in the material was much higher than that ofN_2 or Ar. During prolonged sintering, the density of specimensdecreased, while the amount of emitted gas increased. Entrappedgases in the sintered body were concluded to bring about thedensity decrease during grain growth.