快速成型制造, also known as 3D printing, is revolutionizing manufacturing across industries from aerospace to medical devices. One key area of advancement is in metal 3D printing, which allows complex metal parts to be created directly from 3D CAD models without the need for expensive tooling or molds.
Metal additive manufacturing requires specialized equipment and materials to achieve the extreme temperatures needed to melt and fuse metal powders into solid objects. The most common metal 3D printing technologies used today are powder bed fusion, directed energy deposition, binder jetting, and sheet lamination.
The material properties of parts produced through metal 3D printing depend greatly on the composition and characteristics of the metal powders and alloys used. This article provides an overview of the most common metal additive manufacturing materials, their properties, applications, and suppliers.
Metal Additive Manufacturing Materials Types
There are a wide range of metal alloys available for powder-based 3D printing. The most commonly used include:
| 材料 | 说明 |
|---|---|
| 不锈钢 | Iron-based alloys with chromium, nickel, manganese, molybdenum, titanium, copper. Corrosion-resistant, high strength. |
| 铝合金 | Al-Si, Al-Si-Mg alloys. Low density, high thermal conductivity. |
| 钛合金 | Ti-6Al-4V, Ti-6Al-4V ELI. Excellent strength-to-weight ratio, biocompatibility. |
| 镍合金 | Inconel 625, 718. Heat and corrosion resistance. Used in aerospace components. |
| 钴铬合金 | CoCrMo alloy. Biocompatible, high hardness. Used for dental implants and joints. |
| 贵金属 | Gold, silver, platinum. Electrical conductivity, corrosion resistance, aesthetics. |
| 工具钢 | H13, maraging steel. High hardness, heat treatable. For tooling and molds. |
| 铜合金 | CuZn, bronze alloys. Electrical and thermal conductivity. |
These base materials can be blended and alloyed in various combinations to achieve specific material properties needed for different applications.
Metal Additive Manufacturing Materials Properties
The key properties of metal powders used in additive manufacturing include:
粒径分布
- Powder particle size is typically 15-45 microns for powder bed fusion.
- Smaller particles <15 microns improve density but reduce flowability.
- Larger particles >45 microns reduce precision and surface finish.
- Uniform size distribution allows optimal packing density.
Morphology and shape
- Spherical powder shape allows smooth flow and packing.
- Irregular shapes can cause poor bulk density and powder bed uniformity.
流动性
- Powders must spread evenly across the powder bed for uniform layers.
- Flowability determined by shape, size distribution, surface texture.
- Flow agents may be added to improve powder flow.
密度
- Higher packing density of powder leads to reduced porosity in printed parts.
- Apparent density typically 40-60% of true solid density.
- Tapped density indicates flow and packing efficiency.
纯净
- High purity reduces defects and contamination.
- Oxygen, nitrogen levels kept below 100 ppm.
- Minimal satellites (small particles attached to larger ones).
水分含量
- Moisture can cause powder clumping and reduce flow.
- Moisture content kept below 0.02% by weight.
- Powders stored in vacuum or inert gas atmosphere.
In addition to powder characteristics, the composition and microstructure of the bulk metal alloys impart important performance properties to AM parts:
实力
- Yield strength 500 MPa to over 1 GPa depending on alloy.
- Heat treatment can increase strength through precipitation hardening.
硬度
- Vickers hardness from 150 HV to over 400 HV.
- Hardness can be tailored locally through heat treatment.
密度
- Near full density >99% can be achieved.
- Residual porosity depends on process parameters.
表面处理
- As-printed surface is rough 10-25 microns Ra.
- Machining, grinding, polishing required for precision finish.
抗疲劳性
- Comparable to wrought materials but anisotropic.
- Depends on build orientation, internal defects.
耐腐蚀性
- Varies significantly by alloy composition from low to very high.
热性能
- Conductivity and expansion coefficients close to wrought alloys.
- Depending on build orientation due to microstructure.
电阻率
- Within 10-20% of wrought materials.
- Higher porosity increases resistivity.
By selecting optimized powders and alloys, metal AM enables the fabrication of dense parts with mechanical properties comparable to traditional manufacturing in many cases. However, properties remain anisotropic depending on build direction.
Metal Additive Manufacturing Materials Applications
The key applications taking advantage of metal additive manufacturing include:
航空航天 Complex jet engine, rocket, and hypersonic vehicle components. Reduced weight, increased performance.
医疗 Custom orthopedic implants, prosthetics, surgical tools. Biocompatible metals tailored to anatomy.
汽车 Lightweighting components, performance parts, tooling. Increased strength and functional integration.
工业 End-use production parts for pumps, compressors, engines. Reduced lead time and inventory.
Consumer: Jewelry, fashion accessories, small gadgets. Unique high-value geometries.
Defense: Rugged parts for field use, protective gear, armament. On-demand manufacturing.
Moldmaking: Conformal cooling channels give higher productivity. Direct printing of mold tooling.
Energy: Oil/gas components resist corrosion and perform in extreme environments.
The excellent mechanical properties, accuracy and design freedom enabled by metal AM make it valuable for prototypes, tools, and end-use production parts across many industries.
Metal Additive Manufacturing Process Capabilities
The different metal 3D printing processes have varying capabilities in terms of compatible materials, part sizes, accuracy, surface finish and more:
| 过程 | 材料 | 准确性 | Finish | 速度 |
|---|---|---|---|---|
| 粉末床融合 | 大多数合金 | ±0.1-0.2mm | Rough, porous | 中型 |
| 定向能量沉积 | Any alloy | ±0.3-1mm | 粗糙 | 高 |
| 粘结剂喷射 | 大多数合金 | ±0.2mm | Infiltration required | 高 |
| 板材层压 | 大多数合金 | ±0.1mm | 良好 | 慢 |
Powder bed fusion offers the best accuracy and surface finish but slower speeds. 定向能量沉积 allows large near-net shape parts to be built rapidly but with lower precision. 粘结剂喷射 is faster but requires infiltration for full density. Sheet lamination is limited to thinner sections.
The optimal process depends on the application requirements – choose based on part size, material options, accuracy, speed and post-processing needs.
Popular Metal Additive Manufacturing Alloy Systems
Here are some of the most common metal alloy systems used in additive manufacturing along with their key characteristics:
不锈钢
| 合金 | 组成 | 属性 | 应用 |
|---|---|---|---|
| 17-4PH | 铬、镍、铜 | High strength, corrosion resistance | Aerospace, industrial |
| 15-5PH | 铬、镍 | 沉淀硬化 | 航空航天、汽车 |
| 316L | 铬、镍、钼 | Corrosion resistance, bio-compatible | Medical, marine |
| 304L | 铬、镍 | 耐腐蚀性 | 消费品 |
铝合金
| 合金 | 组成 | 属性 | 应用 |
|---|---|---|---|
| AlSi10Mg | Al, Si, Mg | Low density, good strength | 航空航天、汽车 |
| AlSi7Mg | Al, Si, Mg | Low density, high ductility | Automotive, consumer |
| A2024 | Al, Cu, Mg | 高强度 | 航空航天结构 |
| Al6061 | Al, Mg, Si | Medium strength, corrosion resistance | Aerospace, marine |
钛合金
| 合金 | 组成 | 属性 | 应用 |
|---|---|---|---|
| Ti6Al4V | 钛、铝、钒 | 高强度重量比 | 航空航天、医疗 |
| Ti6Al4V ELI | Low interstitials | Fracture resistance | 航空航天 |
| Ti64 | 钛、铝、钒 | Heat treatability | 航空航天、汽车 |
| Ti 2 级 | Ti | 卓越的耐腐蚀性 | Industrial, marine |
镍合金
| 合金 | 组成 | 属性 | 应用 |
|---|---|---|---|
| 铬镍铁合金 718 | Ni, Fe, Cr | High strength, corrosion resistance | Aerospace, oil and gas |
| 铬镍铁合金 625 | Ni, Cr, Mo | 抗氧化和抗腐蚀 | Aerospace, chemical |
| 哈氏合金 X | Ni, Fe, Cr | Oxidation resistance, high temp | Aerospace, industrial |
Cobalt Chrome Alloys
| 合金 | 组成 | 属性 | 应用 |
|---|---|---|---|
| 钴铬钼合金 | Co, Cr, Mo | Biocompatible, high hardness | Medical implants, dental |
| CoCrWNi | Co, Cr, W, Ni | High hardness, strength | Dental, cutting tools |
| CoCrMoSi | Co, Cr, Mo, Si | Biocompatible, high fatigue strength | 医疗植入物 |
By selecting the optimal alloy for the application requirements, additive manufacturing enables high performance metal parts to be 3D printed on demand.
Popular Metal Powder Grades for Additive Manufacturing
Most major metal powder suppliers now provide optimized powder grades specifically for additive manufacturing. Here are some of the most common grades used:
不锈钢粉
| 材料 | 粉末等级 | 颗粒大小 | 供应商 |
|---|---|---|---|
| 17-4PH | Philloy 17-4, 17-4PH NX2 | 15-45 微米 | Hoganas, Carpenter Additive |
| 316L | 316L CX, 316L-Si-dura | 15-45 微米 | Linde, Concept Laser |
| 304L | CL20ES, 304L CX | 15-45 微米 | Concept Laser, Carpenter Additive |
铝合金粉
| 材料 | 粉末等级 | 颗粒大小 | 供应商 |
|---|---|---|---|
| AlSi10Mg | AlSi10Mg ALEA, AlSi10Mg CX | 25-45 微米 | Linde, Concept Laser |
| AlSi7Mg | AlSi7Mg AM | 25-45 微米 | Linde |
| Al6061 | 6061 CX | 15-45 微米 | 木匠添加剂 |
Titanium Alloy Powders
| 材料 | 粉末等级 | 颗粒大小 | 供应商 |
|---|---|---|---|
| Ti6Al4V | Ti64 ELIT, Ti64 Grade 23 | 15-45 微米 | AP&C, Linde |
| Ti6Al4V ELI | Ti64-ELI CX | 15-45 微米 | 木匠添加剂 |
镍合金粉
| 材料 | 粉末等级 | 颗粒大小 | 供应商 |
|---|---|---|---|
| 铬镍铁合金 718 | 718 ALEA AM, 718-P Powder | 10-45 微米 | Linde, Praxair |
| 铬镍铁合金 625 | 625 CX, Inconel 625-Si-dura | 15-45 微米 | Carpenter Additive, Concept Laser |
Cobalt Chrome Alloy Powders
| 材料 | 粉末等级 | 颗粒大小 | 供应商 |
|---|---|---|---|
| 钴铬钼合金 | CoCrMo CX, Digital CobaltChrome | 5-25 微米 | Carpenter Additive, Arcam |
| CoCrWNi | CC W-Ni CX | 5-25 微米 | 木匠添加剂 |
These optimized powder grades ensure high quality and repeatable performance for metal additive manufacturing across common aerospace, medical, and industrial alloys.
Metal Additive Manufacturing Powder Costs
The costs of metal powders for AM can vary significantly depending on alloy composition, purity, particle size distribution, supplier, and purchase volume:
| 材料 | 每公斤费用 |
|---|---|
| 不锈钢 316L | $50 – $120 |
| 铝 AlSi10Mg | $50 – $100 |
| 钛合金 Ti64 | $150 – $500 |
| 铬镍铁合金 718 | $150 – $300 |
| 钴铬合金 | $250 – $500 |
Powder cost is a significant portion of overall part cost in metal AM. Industries adopting AM include aerospace, medical, automotive, and oil and gas where high-value alloys justify the costs. As volumes increase, prices are declining. Reusing waste powder via powder recovery systems also helps reduce overall costs per part.
Metal Additive Manufacturing Post-Processing
Most metal AM processes produce parts with a rough surface finish and some internal porosity. Additional post-processing is typically required:
- Removal from build plate – Cutting, grinding, or wire EDM to remove supports and separate parts.
- 表面处理 – Machining, grinding, polishing, blasting to improve surface finish.
- 缓解压力 – Heat treatment to relieve residual stresses from AM build.
- 热等静压 – High pressure to eliminate internal voids and increase density.
- 热处理 – Precipitation hardening, aging to enhance mechanical properties.
- 涂料 – Apply functional coatings for wear/corrosion resistance if needed.
With the right post-processing, metal AM parts can achieve extremely high density and precision surface finishes comparable to traditionally manufactured metal components.
Metal Additive Manufacturing Design Guidelines
To take full advantage of metal AM and avoid potential pitfalls, following design guidelines is recommended:
- Minimize overhanging structures requiring supports
- Orient parts to reduce stair-stepping surface finish effects
- Use thin walls, lattices to reduce weight and material use
- Consolidate assemblies into single complex parts
- Incorporate conformal cooling channels and bionic designs
- Design internal channels and voids to be self-supporting
- Allow access holes for unpowdered regions
- Account for anisotropic properties based on build orientation
- Design generous fillets and radii into corners
By adopting a design-for-AM mindset, engineers can fully leverage these innovative capabilities.
The Future of Metal Additive Manufacturing
Metal additive manufacturing has come a long way in terms of materials, processes, applications and adoption. However, significant opportunities still exist to improve speed, cost, quality, and material options.
Equipment manufacturers are developing larger build envelopes and multi-laser systems to increase productivity. Closed-loop monitoring and advanced quality control systems will help boost consistency and reliability.
Material suppliers are focused on qualifying more alloys optimized for AM, including higher temperature materials like nickel superalloys, tool steels, refractory metals. Functionally graded and composite metal powders will provide more tuning of properties.
软件 advancements around design, simulation, optimization, machine learning, and automation will make AM more accessible to a wider audience. System connectivity and digital manufacturing approaches will allow more distributed and agile production.
应用 will continue growing rapidly in aerospace for engines and structural components. Adoption in automotive, oil and gas, medical devices, and consumer electronics will accelerate as costs decrease. Rapid manufacturing and mass customization will become reality.
It is an exciting time in the metal AM industry as new players and novel innovations enter this high growth market estimated to reach over $15 billion by 2028.
Metal Additive Manufacturing – FAQ
Here are answers to some frequently asked questions about metal additive manufacturing materials and processes:
What types of metals can be 3D printed?
Most major industrial alloys are printable including stainless steels, aluminum, titanium, nickel, cobalt chrome, tool steels, precious metals like gold and silver, and copper alloys. New alloys are constantly being qualified.
What kind of accuracy and finish can be achieved?
Dimensional accuracy is typically around ±0.1-0.3% with tolerances of ±0.1-0.2mm. As-printed surface finish is rough at 10-25 μm Ra but can be improved significantly through machining and polishing.
How do the material properties compare to traditional manufacturing?
The microstructure and properties of most additive parts are comparable to cast or wrought material forms. Mechanical properties meet or exceed standards for materials like aerospace-grade titanium and nickel alloys.
How are parts post-processed after 3D printing?
Post-processing includes support removal, stress relieving, surface finishing operations like CNC machining, grinding, and polishing as well as any heat treatment required. Some critical applications may require hot isostatic pressing (HIP) to eliminate internal voids and increase density.
What are some key design principles for metal AM parts?
Design guidelines include minimizing overhangs, optimizing build orientation, incorporating lattices and internal structures, using thin walls, and consolidating assemblies. Performance can be enhanced through bionic and conformal cooling designs.
