The Importance of Powder Metallurgy Density
In powder metallurgy, density refers to the mass of a substance per unit volume. The higher the density of a product, the better its properties, such as hardness, tensile strength, and fatigue strength. Therefore, increasing the density of powder metallurgy products is an important way to improve product performance.
Classification and Range of Powder Metallurgy Density
Powder metallurgy densities can be divided into low-density and high-density types. Low-density powders, also known as vacuum powders, generally have a specific gravity of 2.6~2.8 g/cm³. After being shaped appropriately, these powders possess high strength and are widely used in aerospace, shipbuilding, and other industries. High-density powders typically have a specific gravity above 4.5 g/cm³. After pressing, they exhibit good toughness and wear resistance, making them suitable for manufacturing small and medium-sized cutting tools, clamping components, and other parts.
Especially for iron-based powder metallurgy, the density range is 5.8 g/cm³ to 7.3 g/cm³. This range is determined by the product's application and structure. For example, products requiring high oil content need to have a lower density to ensure sufficient porosity to accommodate the oil.
Factors Affecting the Density of Powder Metallurgy
Besides material and product requirements, the density of powder metallurgy is also affected by several process parameters. Smaller raw material particle size results in smaller gaps between particles, thus increasing the material's mass density. Simultaneously, increasing the raw material replacement rate, controlling mold temperature, sintering temperature and time, and increasing pressure can all effectively improve the product's mass density.
