After the metal chloride gas and the reducing gas are brought into contact within a reduction reaction temperature range to generate metal powder, when an inert gas such as nitrogen is brought into contact with the metal powder for cooling, the water atomized pure iron powder is cooled from In the range of at least 800 ° C, the cooling rate is above 30 ° C / s. The metal powder is quenched, thereby suppressing the aggregation and growth of the metal powder particles into secondary particles. The particles of the metal powder generated in the reduction step are inhibited from agglomerating and growing into secondary particles after the reduction step, and it is possible to stably obtain ultrafine powder metal powder having a particle diameter of, for example, 1 μm or less.

The metal powders used in the manufacture of diamond tools are mixed powders-except for cobalt powder. Cobalt powder is used alone in the sintering of Jingang 4-stone tools without adding any other powder.

The composition of the mixed metal powder varies depending on the use of the diamond tool. It can be understood that when the diamond saw blade is used to cut hard granite, the mixed metal powder is different from the softer marble. Similarly, the metal powder required for a diamond tool for honing hard steel and a dressing tool for dressing a silicon carbide grinding wheel are different.

However, the composition of the metal mixed powder is not determined by the application alone. The conditions of use of diamond tools will also affect the choice of binder components. For example, the engine power of the drive shaft during cutting has a significant effect on the composition of the tool binder. It is impossible to list all the metal binders required for various diamond tools here.