| 摘要 |
PURPOSE:To easily rough-pulverize Hf crystal bar by pressurizing the high purity Hf crystal bar having high hardness and high toughness in a Ni-base super alloy vessel with Ni-base super alloy pressurizing terminals while cooling this at extremely low temp. coolant. CONSTITUTION:The high purity Hf crystal bar 7 is charged into the Ni-base super alloy vessel 3 coating outer part with heat insulating material 5, and the upper and lower parts thereof are put between the Ni-base super alloy pressurizing terminals 8, 8, and also by flowing the extremely low temp. coolant 2 of liquid Ar, etc., into the vessel 3, the Hf crystal bar is cooled at -150 deg.C to give it brittleness. The Hf crystal bar 7 is pressurized with the upper pressurizing terminal 8 through pressing means 9 at about 9kg/mm<2> pressing force and roughly pulverized. Even to the high purity Hf crystal bar 7 having high strength and high toughness, the brittleness is imparted by cooling at extremely low temp., and also by absorbing and cooling the large quantity of heat caused by emission of the combined energy in the crystal at the time of pulverizing with the coolant 2, the Hf crystal bar 7 can be easily rough-pulverized with the pressing force of about 9kg/mm<2>.
|
