Laser Engineered Net Shaping™
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Sandia National Laboratories has developed a new technology to fabricate three-dimensional metallic components directly from CAD solid models. This process, called Laser Engineered Net ShapingT (LENSŪ), exhibits enormous potential to revolutionize the way in which metal parts, such as complex prototypes, tooling, and small-lot production items, are produced.
The process fabricates metal parts directly from the Computer Aided Design (CAD) solid models using a metal powder injected into a molten pool created by a focused, high-powered laser beam.
Simultaneously, the substrate on which the deposition is occurring is scanned under the beam/powder interaction zone to fabricate the desired cross-sectional geometry. Consecutive layers are sequentially deposited, thereby producing a three-dimensional metal component.
This process is similar to other rapid prototyping technologies in its approach to fabricate a solid component by layer additive methods. However, the LENSŪ technology is unique in that fully dense metal components are fabricated directly from raw materials, bypassing initial forming operations such as casting, forging, and rough machining.
LENS® offers the opportunity to dramatically reduce the time and cost required to realize functional metal parts. As a material additive process, additional cost savings will be realized through increased material utilization as compared to bulk removal processes. LENS® can also be used to modify or repair existing hardware.
Parts have been fabricated from stainless steel alloys, nickel-based alloys, tool steel alloys, titanium alloys, and other specialty materials; as well as composite and functionally graded material deposition. Microscopy studies show the LENSŪ parts to be fully dense with no compositional degradation. Mechanical testing reveals outstanding as-fabricated mechanical properties.
- Ability to build fully dense shapes
- Closed loop control of process for accurate part fabrication
- Ability to tailored deposition parameters to feature size for speed, accuracy, and property control
- Composite and functionally graded material deposition
- Three- and four-axis systems for complex part fabrication
- Wide variety of materials that, at minimum, include: stainless steel alloys (316, 304L, 309, 17-4), maraging steel (M300), nickel-based superalloys (Inco designations 625, 600, 718, 690), tool steel alloys (H13), titanium alloy (6Al-4V), and other specialty materials
- Mechanical properties similar or better than traditional processing methods
- LENS® machine with 4-axis capability (12" x 12" x 12")
- Specialized path planning software for tailored processing (variable deposition parameters, smart path sequencing, multiple materials)
- Closed loop control system to control the molten pool volume
- CAD solid modeling
- State-of-the-art metrology laboratory including: coordinate measuring machine, video measuring system, and non-contact surface analyzer
- Three-dimensional laser digitizing system
- Complete machine shop including: three-, four-, and five-axis computer numerical control (CNC) mills, CNC lathes, electrical discharge machines (wire and sinker), lathes, mills, and grinders
- WES housing hybrid fabrication sequence, high aspect ratio features added by LENS® to simple machined surfaces, allowed for quick turnaround of housing for design verification and testing
- LENS® precision deposition used to complete set of production Kovar braze fixtures to prevent diffusion bonding (fixtures)
- Composite and functionally graded impeller to show geometric and composition precision in multi-material fabrication (impeller)
- Verification of mathematical model of cellular structure, enabling prediction of crush behavior (modes, etc.) (crush modeling)
- Rear load spreader with 95% improvement in material waste over conventional machining
- Tooling for injection molding with conformal cooling channels to improve thermal characteristics in-use (H13 tooling)
- Laser marking, with high strength bonding, on weapon components
- Commercialization of the technology