Laser engineered net shaping (LENS™): A tool for direct fabrication of metal parts

TLDR

Sandia National Laboratories has long developed rapid prototyping and direct fabrication technologies, including laser‑initiated additive methods such as stereolithography and selective laser sintering, to build prototype parts and patterns from CAD data. The authors aim to develop and present Laser Engineered Net Shaping (LENS™), a process that fabricates fully dense metal parts directly from CAD solid models, and to discuss its potential applications. LENS™ builds parts by coordinating metal powder injection into a focused laser‑heated molten pool on a moving substrate, depositing successive layers to create a fully dense three‑dimensional part from CAD data. The process produces complex, fully dense, near‑net‑shape parts from materials such as 316 stainless steel, nickel‑based alloys, HI3 tool steel, and titanium, demonstrating potential to revolutionize production of.

Abstract

For many years, Sandia National Laboratories has been involved in the development and application of rapid prototyping and direct fabrication technologies to build prototype parts and patterns for investment casting. Sandia is currently developing a process called Laser Engineered Net Shaping (LENS™) to fabricate fully dense metal parts directly from computer-aided design (CAD) solid models. The process is similar to traditional laser-initiated rapid prototyping technologies such as stereolithography and selective laser sintering in that layer additive techniques are used to fabricate physical parts directly from CAD data. By using the coordinated delivery of metal particles into a focused laser beam, a part is generated. The laser beam creates a molten pool of metal on a substrate into which powder is injected. Concurrently, the substrate on which the deposition is occurring is moved under the beam/powder interaction zone to fabricate the desired cross-sectional geometry. Consecutive layers are additively deposited, thereby producing a three-dimensional part.This process exhibits enormous potential to revolutionize the way in which metal parts, such as complex prototypes, tooling, and small-lot production parts, are produced. The result is a complex, fully dense, near-net-shape part. Parts have been fabricated from 316 stainless steel, nickel-based alloys, HI3 tool steel, and titanium. This talk will provide a general overview of the LENS™ process, discuss potential applications, and display as-processed examples of parts.