نشریه ریخته گری
پیاپی 134 (تابستان 1402)

In the second part of investigation of metal powder production methods, the gas atomization method is examined in more details. In recent years, gas atomization has received a lot of attention due to its unique capabilities in producing the powder required for the additive manufacturing process. Although, this method has not been exploited newly and the first related patent was published more than 100 years ago. The produced powders in this way are used in different applications on a global scale, from the production of superalloy powders for PM and powders required by the MIM method, even the spherical bronze powders for making filters and necessary materials for soldering, etc. In the rest of this section, other methods of atomization are presented including the mechanical breakdown of the molten jet and its transformation into metal droplets. Some of these processes, such as centrifugal atomization, have been properly established and applied in industrial scale with a capacity of about 50-100 kilotons per year. The ultrasonic atomization method has been commercially used for decades for low temperature alloys, and recent advances have increased its operating temperature and enabled it to process a wide range of alloys. Also, in this section, pressure atomization (or single fluid), which has a very limited application, and also briefly, some two-fluid processes using unconventional fluids (such as oil and cryogenic gas) will be described.