SLSS (Sinterización láser selectiva) and SLM (Derretimiento láser selectivo) are two leading powder-based 3D Tecnologías de impresión, but they differ drastically in how they process materials and deliver part performance. Understanding these differences is critical for choosing the right method—whether you’re making prototypes, componentes industriales, or medical implants. This article breaks down the 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. Fusión)
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.
| Tecnología | Forming Principle | Cómo funciona | Analogía simple |
| SLSS | 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. Comparación de lado a lado: SLS VS. SLM Across 6 Key Areas
To quickly assess which technology fits your needs, use this comprehensive table comparing their laser types, materiales, part performance, y más.
| Comparison Category | SLSS (Sinterización láser selectiva) | SLM (Derretimiento láser selectivo) | Para llevar |
| Tipo láser | – Láseres de co₂ (wavelength: 9.2–10.8 microns)- Lower power density (focused on bonding, not melting). | – Short-wavelength lasers: Nd-YAG (1.064 micras) or fiber lasers (1.09 micras)- Higher power density (needed to fully melt metal). | SLM uses lasers optimized for metal absorption; SLS uses lasers for broader powder compatibility. |
| Materiales utilizados | – Amplio alcance: Polímeros (nylon, poliestireno), rieles (hierro, aleaciones de titanio), cerámica, coated sand.- Metal printing requires binder powders (low-melting-point metals or organic resins) mixed with main metal powder. | – Limited to pure metal powders: Aleaciones de aluminio, aleaciones de titanio, acero inoxidable, cobalt-chromium alloys.- No binders needed—pure metal is melted directly. | SLS offers more material versatility; SLM is specialized for high-performance pure metals. |
| Desempeño parcial | – Porosidad: Contains small gaps (estructura porosa).- Propiedades mecánicas: Lower strength, poor corrosion/wear resistance.- Precisión: Moderado (aspereza de la superficie: Ra 10–20 μm).- Requires post-processing (P.EJ., hot isostatic pressing) to improve density. | – Porosidad: Sin huecos (fully dense structure, >99% densidad).- Propiedades mecánicas: Alta fuerza, excellent corrosion/wear resistance (matches forged metals).- Precisión: Alto (aspereza de la superficie: Ra 5–10 μm).- Minimal post-processing needed for functional use. | SLM produces industrial-grade, piezas de alto rendimiento; SLS parts need upgrades for demanding applications. |
| Estructuras de soporte | – No additional supports needed. Unsintered powder acts as a “natural support” for cavities and cantilevers. | – Requires support structures for complex designs (P.EJ., sobresalientes >45°). Supports prevent deformation/collapse during melting. | SLS simplifies design (no support constraints); SLM needs extra design steps for supports. |
| Calidad de la superficie | – Grainy texture with visible layer lines.- Requires post-processing (pulido, ardor de arena, revestimiento) Para mejorar la apariencia. | – Smoother than SLS, but still has minor layer lines.- May need light polishing for high-aesthetic requirements (P.EJ., implantes médicos). | SLM has better out-of-the-box surface quality; both may need finishing for cosmetic use. |
| Application Fields | – Prototipos (rápido, modelos de bajo costo), fabricación de moldes, bienes de consumo (P.EJ., custom cases), dispositivos médicos (P.EJ., exoskeletons).- Metal use: Partes no críticas (P.EJ., Componentes interiores aeroespaciales, soportes automotrices). | – Piezas de alto rendimiento: Aeroespacial (componentes del motor, hojas de turbina), médico (implantes ortopédicos, coronas dentales), automotor (piezas estructurales livianas), fabricación de moldes (complex runners). | SLS excels at prototypes and low-stress parts; SLM dominates high-performance, Aplicaciones críticas de seguridad. |
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:
Paso 1: Ask About Material Needs
- Need polymers, cerámica, or mixed materials? Elegir SLSS—it’s the only option for non-metal powder printing. Por ejemplo, SLS is ideal for nylon prototypes or ceramic molds.
- Need pure, high-strength metals? Elegir SLM—it processes aluminum, titanio, and stainless steel into dense, piezas duraderas. Por ejemplo, SLM is used for titanium medical implants.
Paso 2: Ask About Part Performance Requirements
- Low-stress applications (P.EJ., display prototypes, non-critical brackets)? Elegir SLSS—its porous parts are cost-effective and sufficient for light use.
- High-stress or safety-critical applications (P.EJ., piezas de motor aeroespacial, implantes médicos)? Elegir SLM—its fully dense structure ensures strength and reliability.
Paso 3: Ask About Cost & Complejidad de diseño
- Tight budget or complex designs with overhangs? Elegir SLSS—no supports reduce design time, y los costos de material son más bajos (P.EJ., nylon powder is cheaper than titanium powder).
- Willing to invest in quality for functional parts? Elegir SLM—while more expensive, it eliminates the need for costly post-processing (P.EJ., hot isostatic pressing for SLS metals).
4. Yigu Technology’s Perspective on SLS vs. SLM
En la tecnología yigu, 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 (rápido, flexible, rentable) and SLM for final production of high-performance parts. For clients transitioning from prototypes to production, we also help optimize designs: For SLS, Simplificamos los voladizos para evitar el posprocesamiento.; para SLM, Minimizamos los soportes para reducir el desperdicio de material.. La clave es alinear la tecnología con sus necesidades de rendimiento y su presupuesto, no elegir una opción "mejor".
Preguntas frecuentes: Common Questions About SLS and SLM Technology
- q: ¿Puede SLS producir piezas metálicas que igualen el rendimiento de SLM con posprocesamiento??
A: No. Incluso con prensado isostático en caliente, Las piezas metálicas SLS solo alcanzan ~95% de densidad (VS. >99% para SLM), lo que lleva a una menor resistencia y resistencia a la corrosión. SLM sigue siendo necesario para piezas metálicas críticas para la seguridad.
- q: ¿Es SLM más caro que SLS??
A: Sí. SLM machines cost 2–3x more than SLS machines, and pure metal powders (P.EJ., titanio) are 5–10x pricier than SLS materials (P.EJ., nylon). Sin embargo, 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 (generalmente <50cm³) due to the need for precise heat control during melting—larger SLM parts risk warping.