Selective laser melting (SLM) is a metal additive manufacturing process that uses a laser to fuse metallic powder into fully dense components. This guide examines SLM technology, systems, materials, applications, benefits, and considerations when implementing additive manufacturing with SLM.
介绍 快速成型制造 SLM
Selective laser melting (SLM) is a powder bed fusion additive manufacturing technique that utilizes a high-power laser to selectively melt and fuse metallic powder particles layer-by-layer to build up fully dense 3D parts directly from CAD data.
Key attributes of SLM technology:
- Uses focused laser beam to melt powdered metals
- Adds material only where required in each layer
- 可实现铸造或机加工无法实现的复杂几何形状
- Creates near-net shape metal components with high density
- Materials include aluminum, titanium, stainless steel, alloys
- Small to medium part build volumes
- Ideal for complex, low-volume parts
- Eliminates need for hard tooling like molds or dies
- Significantly reduces waste compared to subtractive methods
- Enables lightweight designs and part consolidation
- Allows functional improvements with engineered structures
With its capabilities, SLM delivers game-changing benefits for innovative product design and lean manufacturing. However it requires expertise to master the process.
How SLM Additive Manufacturing Works
The SLM production process consists of:
- Spreading and leveling a thin layer of metal powder on a build plate
- Selectively scanning a focused laser beam to melt powder
- Lowering build platform and repeating layering and melting
- Removing completed parts from the powder bed
- Post-processing parts as needed – cleanup, heat treat etc.
Precisely controlling the laser, scan patterns, chamber atmosphere and other parameters is critical to achieve high quality, dense metal parts with SLM.
SLM systems feature a laser generator, beam delivery optics, powder delivery system, build chamber, inert gas handling, and central controls. Performance depends heavily on system engineering and tuning build parameters.
SLM Equipment Manufacturers
Leading global suppliers of SLM additive manufacturing systems include:
| 公司名称 | 机型 | 建筑尺寸范围 | 材料 | 价格范围 |
|---|---|---|---|---|
| SLM 解决方案 | 下一代, NXG XII | 250 x 250 x 300 毫米 <br>500 x 280 x 365 毫米 | 钛、铝、镍、钢 | $400k – $1.5M |
| EOS | M 300、M 400 | 250 x 250 x 325 毫米 <br> 340 x 340 x 600 毫米 | 钛、铝、镍、铜、钢、钴铬合金 | $500k – $1.5M |
| Trumpf | TruPrint 3000 | 250 x 250 x 300 毫米 <br> 500 x 280 x 365 毫米 | 钛、铝、镍、铜、钢 | $400k – $1M |
| 概念激光器 | X 线 2000R | 800 x 400 x 500 毫米 | 钛、铝、镍、钢、钴铬合金 | $1M+ |
| 雷尼绍 | AM400, AM500 | 250 x 250 x 350 毫米 <br>395 x 195 x 375 毫米 | 钛、铝、钢、钴铬合金、铜 | $500k – $800k |
System selection depends on build size needs, materials, quality, cost, and service support. Partnering with an experienced SLM solutions provider is recommended to properly evaluate options.
SLM 工艺特点
SLM 涉及各种工艺参数之间复杂的相互作用。以下是其主要特点：
激光 – Power, wavelength, mode, scanning speed, hatch spacing, strategy
粉末 - 材料、颗粒大小、形状、进料速度、密度、流动性、重复利用率
温度 - 预热、熔化、冷却、热应力
氛围 - 惰性气体类型、氧气含量、流速
构建板 - 材料、温度、涂层
扫描策略 - 填充图案、旋转、边框轮廓
支持 – Minimizing, interface, removal
后期处理 - 热处理、HIP、机加工、精加工
Understanding relationships between these parameters is essential to achieve defect-free parts with optimized mechanical properties.
SLM Part Design Guidelines
Proper part design is critical for successful SLM additive manufacturing:
- Design with AM principles in mind vs conventional methods
- Optimize geometries to reduce weight, material use, improve performance
- 使用自支撑角钢，尽量减少对支撑物的需求
- 在设计中允许支持界面区域
- 确定部件的方向，以减少应力和避免缺陷
- Account for thermal shrinkage effects in features
- 设计用于清除未熔化粉末的内部通道
- Address potential warpage in overhangs or thin sections
- 设计表面光洁度时考虑到竣工时的粗糙度
- 考虑层线对疲劳性能的影响
- Design fixturing interface for removing parts from powder bed
- 尽量减少未烧结粉末的滞留量
Simulation software helps assess stresses and deformations in complex SLM parts before printing.
SLM 材料选项
A range of alloys can be processed with SLM technology, with final material properties dependent on parameters:
| 类别 | 普通合金 |
|---|---|
| 钛 | Ti-6Al-4V, Ti 6242, TiAl, Ti-5553 |
| 铝质 | AlSi10Mg、AlSi12、Scalmalloy |
| 不锈钢 | 316L、17-4PH、304L、4140 |
| 工具钢 | H13、马氏体时效钢、铜工具钢 |
| 镍合金 | 铬镍铁合金 625、718、海恩 282 |
| 钴铬合金 | 钴铬钼合金、MP1、钴铬钨合金 |
| 贵金属 | 金、银 |
Choosing compatible alloys and dialing in qualified build parameters are essential to achieve required material performance.
关键 SLM 应用
可持续土地管理实现了各行各业的转型能力：
| 行业 | Typical SLM Applications |
|---|---|
| 航空航天 | Turbine blades, impellers, UAV components |
| 医疗 | 骨科植入物、手术工具、病人专用器械 |
| 汽车 | 组件轻量化、定制工具 |
| 能源 | 复杂的油气阀门、热交换器 |
| 工业 | 共形冷却刀片、夹具、固定装置、导轨 |
| 国防 | Drones, firearms, vehicle & body armor components |
与传统制造相比，其优势包括
- 大规模定制能力
- 缩短开发时间
- 自由设计，提高性能
- 部件合并和轻量化
- 消除过度使用材料的现象
- 供应链整合
在关键应用中使用 SLM 零件时，需要对机械性能进行仔细验证。
的利弊 SLM 快速成型制造
优势
- Design freedom enabled through additive process
- Complexity achieved without increased costs
- Eliminates need for hard tooling like molds or dies
- Consolidates subassemblies into single components
- Lightweighting from organic, topology optimized structures
- 定制和小批量生产
- Reduced development time versus casting/machining
- High strength-to-weight ratio from fine microstructures
- Greatly minimizes material waste versus subtractive processes
- 及时生产和分散生产
- 减少部件交付周期和库存
局限性：
- 与其他金属 AM 工艺相比，制造量更小
- Lower accuracy and surface finish than CNC machining
- Limited choice of qualified alloys compared to casting
- 通过大量试错来优化构建参数
- Anisotropic material properties from layer-by-layer buildup
- Potential for residual stress and cracking defects
- Powder removal difficulties from complex internal geometries
- Often requires post-processing to achieve final properties
- 设备成本高于聚合物三维打印
- 需要特殊设施和惰性气体处理
如果应用得当，可持续土地管理可实现其他手段无法实现的突破性性能。
Implementing SLM Additive Manufacturing
Key steps when adopting SLM technology include:
- 根据需求确定合适的应用程序
- 确认所选设计的可持续土地管理可行性
- 制定严格的工艺鉴定协议
- 投资合适的 SLM 设备
- 确保金属粉末床工艺的专业性
- Establishing stringent material quality procedures
- Mastering parameter development and optimization
- 实施稳健的后处理方法
- 鉴定成品部件的机械性能
A methodical introduction plan focused on low-risk applications minimizes pitfalls when adding SLM additive capabilities. Partnering with experienced SLM service bureaus or system OEMs provides access to expertise.
SLM 生产成本分析
可持续土地管理生产的经济性涉及
- 机器设备成本高
- 构建设置、后期处理和质量控制所需的人工
- Material costs of suitable metal powder feedstock
- 零件精加工--机加工、钻孔、去毛刺等。
- Overhead – facilities, inert gas, maintenance
- Initial trial-and-error process development
- Costs decline with production experience and volume
- Becomes economical at volumes around 1-500 units
- 为复杂几何形状提供最高成本优势
Choosing qualified alloys from reputable suppliers is recommended to prevent defects. Partnering with a service provider offers a faster and lower risk adoption path.
SLM 与其他工艺的比较
| 过程 | 与 SLM 的比较 |
|---|---|
| 数控加工 | SLM 可加工减法工艺无法加工的复杂形状。无需硬模具。 |
| 金属注射成型 | SLM has no high tooling costs. Better material properties than MIM. |
| 压铸 | SLM 的模具成本更低。没有尺寸限制。可实现非常复杂的几何形状。 |
| 板材层压 | 与层压复合材料相比，SLM 可制造出完全致密且各向同性的材料。 |
| 粘结剂喷射 | SLM creates fully dense green parts versus porous binder jetted parts requiring sintering. |
| DMLS | SLM provides higher accuracy and better material properties than polymer DMLS. |
| EBM | 与 SLM 相比，电子束熔化的制造率更高，但分辨率较低。 |
Each process offers specific advantages based on the application requirements, batch size, materials, and performance needs.
SLM 快速成型技术的未来展望
可持续土地管理将在未来几年实现大幅增长，其驱动因素包括
- 不断扩大材料范围，提供更多合金
- 建造量更大，可实现工业规模生产
- Improved surface finishes and tighter tolerances
- 提高系统可靠性和生产率
- New hybrid systems integrating CNC machining
- Declining costs improving business case viability
- 进一步优化算法和模拟
- Automated support removal and post-processing
- 监管行业合格部件的增长
- Continued advancement of high complexity designs
可持续土地管理将成为主流，其应用范围将不断扩大，其能力将带来明显的竞争优势。
常见问题
What materials can you process with SLM technology?
Titanium, aluminum, stainless steels, tool steels, nickel alloys, and cobalt chrome are commonly processed.
SLM 有多精确？
典型的精度约为±0.1-0.2%，最小特征分辨率约为 100 微米。
What is the cost of SLM systems?
SLM equipment ranges from $300,000 to $1,000,000+ depending on size, capabilities, and options.
需要进行哪些类型的后期处理？
Heat treating, HIP, surface finishing, and/or machining may be utilized. Support removal is also needed.
What industries use SLM additive manufacturing?
Aerospace, medical, automotive, industrial, and defense sectors are early adopters of SLM.
SLM 对哪些材料效果不佳？
Highly reflective metals like copper or gold remain challenging. Material properties for some alloys are still emerging.
What surface finishes can be achieved?
As-built SLM surface roughness ranges from 5-15 microns Ra. Finishing can further improve this.
SLM 能制造多大的零件？
Standard build volumes range up to 500mm x 500mm x 500mm. Larger machines accommodate bigger components.
Is SLM suitable for end-use production parts?
Yes, SLM is being used increasingly for final production components, with examples in aerospace and medical industries.
