SLS (Selektives Lasersintern) und SLM (Selektives Laserschmelzen) are two leading powder-based 3D printing technologies, Sie unterscheiden sich jedoch erheblich in der Art und Weise, wie sie Materialien verarbeiten und die Leistung der Teile liefern. Das Verständnis dieser Unterschiede ist entscheidend für die Wahl der richtigen Methode – unabhängig davon, ob Sie Prototypen herstellen, Industriekomponenten, oder medizinische Implantate. Dieser Artikel schlüsselt die auf core differences between SLS and SLM technology across 7 key areas, plus guidance on when to use each.
1. Core Difference 1: Forming Principle (Sintering vs. Schmelzen)
The fundamental divide between SLS and SLM lies in how they interact with powder materials—a contrast that defines every other aspect of their performance.
| Technologie | Forming Principle | Wie es funktioniert | Simple Analogy |
| SLS | Selective Sintering | Uses an infrared laser to heat powder particles to a temperature just below their melting point. This creates bonds between particles but leaves the powder not fully melted. Layers are stacked and sintered sequentially to form the final part. | Baking cookies: Dough particles stick together when heated (but don’t turn into a liquid) to form a solid cookie. |
| SLM | Selective Melting | Uses a high-power laser to fully melt metal powder particles into a liquid state. The liquid metal then cools and solidifies completely. Layers are melted and stacked to build the part with a dense, fully fused structure. | Melting metal in a foundry: Metal is heated until it’s liquid, poured into a mold, and cools to form a solid, dense component. |
2. Side-by-Side Comparison: SLS vs. SLM Across 6 Key Areas
To quickly assess which technology fits your needs, use this comprehensive table comparing their laser types, Materialien, part performance, und mehr.
| Comparison Category | SLS (Selektives Lasersintern) | SLM (Selektives Laserschmelzen) | Key Takeaway |
| Laser Type | – CO₂ lasers (wavelength: 9.2–10.8 microns)- Lower power density (focused on bonding, not melting). | – Short-wavelength lasers: Nd-YAG (1.064 Mikrometer) or fiber lasers (1.09 Mikrometer)- Higher power density (needed to fully melt metal). | SLM uses lasers optimized for metal absorption; SLS uses lasers for broader powder compatibility. |
| Materials Used | – Große Auswahl: Polymere (Nylon, Polystyrol), Metalle (iron, Titanlegierungen), Keramik, coated sand.- Metal printing requires binder powders (low-melting-point metals or organic resins) mixed with main metal powder. | – Begrenzt auf pure metal powders: Aluminiumlegierungen, Titanlegierungen, Edelstahl, cobalt-chromium alloys.- No binders needed—pure metal is melted directly. | SLS offers more material versatility; SLM is specialized for high-performance pure metals. |
| Teilleistung | – Porosity: Contains small gaps (porous structure).- Mechanical properties: Lower strength, poor corrosion/wear resistance.- Präzision: Mäßig (Oberflächenrauheit: Ra 10–20 μm).- Requires post-processing (z.B., hot isostatic pressing) to improve density. | – Porosity: No gaps (fully dense structure, >99% Dichte).- Mechanical properties: Hohe Festigkeit, excellent corrosion/wear resistance (matches forged metals).- Präzision: Hoch (Oberflächenrauheit: Ra 5–10 μm).- Minimal post-processing needed for functional use. | SLM produces industrial-grade, Hochleistungsteile; SLS parts need upgrades for demanding applications. |
| Stützstrukturen | – No additional supports needed. Unsintered powder acts as a “natural support” for cavities and cantilevers. | – Requires support structures for complex designs (z.B., Überhänge >45°). Supports prevent deformation/collapse during melting. | SLS simplifies design (no support constraints); SLM needs extra design steps for supports. |
| Oberflächenqualität | – Grainy texture with visible layer lines.- Requires post-processing (Polieren, Sandstrahlen, Beschichtung) um das Aussehen zu verbessern. | – Smoother than SLS, but still has minor layer lines.- May need light polishing for high-aesthetic requirements (z.B., medizinische Implantate). | SLM has better out-of-the-box surface quality; both may need finishing for cosmetic use. |
| Application Fields | – Prototyping (schnell, low-cost models), mold manufacturing, Konsumgüter (z.B., custom cases), medizinische Geräte (z.B., exoskeletons).- Metal use: Unkritische Teile (z.B., Innenraumkomponenten für die Luft- und Raumfahrt, Kfz-Halterungen). | – Hochleistungsteile: Luft- und Raumfahrt (Motorkomponenten, Turbinenschaufeln), medizinisch (orthopädische Implantate, Zahnkronen), Automobil (leichte Strukturteile), mold manufacturing (complex runners). | SLS excels at prototypes and low-stress parts; SLM dominates high-performance, safety-critical applications. |
3. When to Choose SLS vs. SLM? (Step-by-Step Decision Guide)
Use this linear, question-driven process to match the technology to your project’s goals:
Schritt 1: Ask About Material Needs
- Need polymers, Keramik, or mixed materials? Wählen SLS—it’s the only option for non-metal powder printing. Zum Beispiel, SLS is ideal for nylon prototypes or ceramic molds.
- Need pure, high-strength metals? Wählen SLM—it processes aluminum, Titan, and stainless steel into dense, langlebige Teile. Zum Beispiel, SLM is used for titanium medical implants.
Schritt 2: Ask About Part Performance Requirements
- Low-stress applications (z.B., display prototypes, non-critical brackets)? Wählen SLS—its porous parts are cost-effective and sufficient for light use.
- High-stress or safety-critical applications (z.B., Teile für Luft- und Raumfahrtmotoren, medizinische Implantate)? Wählen SLM—its fully dense structure ensures strength and reliability.
Schritt 3: Ask About Cost & Design Complexity
- Tight budget or complex designs with overhangs? Wählen SLS—no supports reduce design time, and material costs are lower (z.B., nylon powder is cheaper than titanium powder).
- Willing to invest in quality for functional parts? Wählen SLM—while more expensive, it eliminates the need for costly post-processing (z.B., hot isostatic pressing for SLS metals).
4. Yigu Technology’s Perspective on SLS vs. SLM
Bei Yigu Technology, we see SLS and SLM as complementary tools for different stages of product development. Many clients overspecify SLM for prototypes—for example, using SLM to make a metal display model when SLS (with metal-polymer powder) would be 40–50% cheaper. We recommend SLS for initial prototyping (schnell, flexibel, kostengünstig) and SLM for final production of high-performance parts. For clients transitioning from prototypes to production, we also help optimize designs: For SLS, we simplify overhangs to avoid post-processing; for SLM, we minimize supports to reduce material waste. The key is to align the technology with your performance needs and budget—not to choose a “better” option.
FAQ: Common Questions About SLS and SLM Technology
- Q: Can SLS produce metal parts that match SLM’s performance with post-processing?
A: NEIN. Even with hot isostatic pressing, SLS metal parts only reach ~95% density (vs. >99% for SLM), leading to lower strength and corrosion resistance. SLM is still required for safety-critical metal parts.
- Q: Is SLM more expensive than SLS?
A: Ja. SLM machines cost 2–3x more than SLS machines, and pure metal powders (z.B., Titan) are 5–10x pricier than SLS materials (z.B., Nylon). Jedoch, SLM eliminates post-processing costs for metal parts, balancing expenses for high-volume projects.
- Q: Can SLS or SLM print large parts?
A: Both have size limits, but SLS typically handles larger parts (up to 1m³) because unsintered powder supports bigger structures. SLM is limited to smaller parts (normalerweise <50cm³) due to the need for precise heat control during melting—larger SLM parts risk warping.