PM VS MIM

?When we mention the powders. We thought PM and MIM were the same technology. Actually, they have a lot of differences. I will show you their differences in this article. It will help you choose the best technology to lower your costs and produce the best products. There are significant differences in their principles, processes, applicable scenarios, costs, and product characteristics.
Process Principles and Steps:
✅PM involves filling metal powders into a rigid mold, then using high pressure (typically 100-800 MPa) to compact the powders into a "green part." This is followed by high-temperature sintering to bind the powder particles. MIM mixes fine metal powders with polymer binders to create a "feedstock," which is then injection molded into complex "green parts." The binders are then removed through debinding, followed by high-temperature sintering to achieve high-density parts.
✅Applicable Shapes and Complexity:
PM is suitable for relatively simple 2D parts (e.g., gears, bushings) but struggles with complex geometries like undercuts and intricate internal features. In contrast, MIM excels at small, highly complex 3D parts with thin walls, threads, and micro-features due to its design flexibility.
✅Precision and Surface Quality:
PM parts generally have lower precision and rougher surfaces, often requiring secondary finishing. MIM can achieve tight tolerances (±0.3% to ±0.5%, even ±0.1%) and excellent surface finishes (Ra 0.8-1.6 μm), typically eliminating the need for additional processing.
✅Materials and Density:
PM uses coarser powders, resulting in lower part densities (often below theoretical) and more modest mechanical properties. MIM leverages ultra-fine spherical powders, enabling sintered densities above 96% (up to 99%) with isotropic, near-forged mechanical performance.
✅Cost and Batch Suitability:
PM has lower tooling costs and higher production efficiency, making it more economical for large batches of simple parts.MIM has higher upfront investments in tooling and process complexity, but is better suited for high-volume, high-precision, and complex geometries; small batches are less economical.
?‍?In summary, ?if the part is simple in shape, requires massive production volumes, and cost is a primary concern, PM pressing is the more efficient and cost-effective choice. ?For complex geometries, high precision, and stringent mechanical requirements, MIM offers distinct advantages, though at a higher cost and process complexity.