| 摘要 |
One of the processes comprises jetting injection water having a liquid temperature of 10°C or lower and an injection pressure of 5 MPa or higher against a flow of molten metal to divide the flow of molten metal into metal particles and cool the metal particles, thereby obtaining a water-atomized metal powder. The cooling with injection water having a liquid temperature of 10°C or lower and an injection pressure of 5 MPa or higher has no film boiling region from initiation of the cooling, and the metal is cooled in a transition boiling region, thereby rendering accelerated cooling possible. It is hence easy to rapidly cool the metal to such a degree that the metal powder can be made amorphous. Also provided is a process wherein a flow of molten metal is divided by jetting an inert gas thereagainst and the resultant metal particles are cooled using injection water having a liquid temperature of 10°C or lower and an injection pressure of 5 MPa or higher, thereby forming a gas-atomized metal powder. Preferably, the cooling with injection water of the metal particles formed by the dividing is conducted after the temperature of the metal particles has fallen to the MHF point or below. |
