1. PM vs MIM Powder Metallurgy: Core Performance Differences
| Metric | PM (Press & Sinter) | MIM (Metal Injection Molding) | Analysis |
|---|---|---|---|
| Density | 85-93% | 96-99% | MIM ↑10-15% denser |
| Tensile Strength | 200-500 MPa (iron-based) | 500-1,000 MPa (same material) | MIM ↑50-100% stronger |
| Surface Roughness (Ra) | 6.3-12.5μm | 1.6-3.2μm | MIM 3-5x smoother |
| Dimensional Tolerance | ±0.5% | ±0.3% | MIM more precise |
| Design Complexity | Simple geometries (gears, bushings) | Complex structures (internal cavities, 0.2mm thin walls) | MIM offers superior freedom |
Case Study: An automotive gear manufacturer produced 100k gears via PM at $0.8/pc. Switching to MIM increased costs to $1.2/pc but tripled fatigue life.
2. Cost Breakdown: PM vs MIM Powder Metallurgy
| Cost Factor | PM Process | MIM Process | Analysis |
|---|---|---|---|
| Tooling Cost | $5k-$15k (steel molds) | $20k-$80k (carbide molds) | PM tooling 60% cheaper |
| Material Utilization | 80-90% | 95-98% | MIM reduces waste by 50% |
| Unit Cost (10k pcs) | $0.5-$1.5 (iron-based) | $1.5-$4.0 (stainless steel) | PM better for ultra-low-cost simple parts |
| Post-Processing Cost | Requires oil impregnation/machining | Often none needed | MIM saves post-processing |
3. Applications: How to Choose Between PM and MIM?
PM Strengths
- Simple geometries: Oil-impregnated bearings, brake pads, appliance gears.
- Ultra-high volumes (>1M pcs): Unit cost drops to ~$0.1/pc after tooling amortization.
- Low-cost iron-based materials: E.g., Fe-Cu-C alloys.
MIM Advantages
- Complex micro-parts (<100g): Surgical tool joints, 3C electronics components.
- High-performance materials: Stainless steel 316L, titanium alloys.
- Multi-material flexibility: Single machine for diverse materials.
Video Explanation:
Watch PM vs MIM Powder Metallurgy Process Comparison