Discuss Green Manufacturing Technology: Powder Metallurgy

What is Powder Metallurgy

Powder metallurgy, as the name suggests, is a processing method that uses metal powder as raw material, which is pressed and sintered to make various products. This isn't a new technology or process, tracing as far back as ancient Egypt. However, in today's pursuit of sustainable and green development, it aligns with the trends of our times and has found increasing applications.

Process Overview

Powder metallurgy is similar to forging or casting processes, but differs in that its raw materials are metal powders (commonly iron, steel, copper, etc.). The powdered raw materials are pressed at room temperature (or heated under special conditions) using complex molds. The dimensions of the pressed workpieces are close to the final product, but their mechanical properties are still unstable. To further strengthen them, sintering is carried out at a temperature close to but slightly lower than the melting point of the used metals. During this process, the microstructure of the product changes, resulting in a highly precise, strong component.

Generally, components produced by powder metallurgy, especially cemented carbide products, can be used directly. However, secondary processing such as finishing, heat treatment, electroplating or coating, and shot peening may be performed as needed to enhance or improve the tolerance, density, strength, shape, corrosion resistance, and other properties of the parts.

Advantages of Powder Metallurgy Products

Compared to other manufacturing techniques, tungsten carbide powder metallurgy almost produces no material waste, with material utilization rates exceeding 97%. This advanced process allows the direct forming of complex geometric shapes while maintaining tight dimensional tolerance control in sintered products, which can reduce or even eliminate machining operations found in traditional manufacturing processes. This is why it is often referred to as a green manufacturing technology.

Beyond these process-related savings, powder metallurgy products have their unique characteristics. By leveraging the advantage of powdered raw materials, it enables controls that are difficult or impossible to achieve in traditional machining, such as chemical composition ratios, control over microstructure, control over porosity, and more.