Freeform Fabrication: Current Research in the USA

J.J. Beaman and Dave BourellUniversity of Texas at Austin

Laboratory for Freeform Fabrication

Introduction to WTEC

World Technology Evaluation Center (WTEC), Inc.

2809 Boston St., #441

Baltimore, MD 21224

October 2003

WTEC Mission• Look for good ideas abroad

(technology transfer)• Identify opportunities for cooperation• Compare U.S. R&D with related

international activities (benchmarking)• Provide information useful for planning

future U.S. R&D activities

Key WTEC Principles

• Open sources and open dissemination (http://www.wtec.org)

• Mutually beneficial exchange of ideas among hosts and WTEC visiting delegations

• Review of drafts by hosts and WTEC prior to public dissemination; proprietary considerations honored

WTEC Assessments Since 1989

• Electronics (11 fields assessed) • Materials (9)• Computer Science (5)• Telecommunications (3)• Biotechnology (3)• Energy (4)• Others (14)

Full text reports posted at http://www.wtec.org

• Biosensing (Schultz, Mrksich et al.) – NIH, NSF, NASA, ARO, USDA

• Benign Manufacturing (Gutowski) – NSF, DOE

• Tissue Engineering (McIntire) – NSF, NIH, FDA, NIST, DARPA, NASA (Academic Press book)

• Spin Electronics (von Molnar) –

NSF, DARPA, OSD, NIST, ONR (Kluwer book)

Recently Completed WTEC Projects

Current WTEC Projects

• Additive/Subtractive Hybrid Manufacturing (Beaman) – NSF, DARPA, ONR, NIST

• OR Applied to Healthcare (Sainfort) – NSF, AHRQ (In Europe Nov. 1)

• Staff Support, National Nanotechnology Initiative & Tissue Engineering Interagency Working Group

Kodama

Herbert

Housholder

Early Parts

Deckard

Complex Objects SLS Fabricated

Consumer Goods25%

Motor Vehicles23%

Medical10%

Business Machines

10%

Other9%

Aerospace9%

Gov/Military7%

Academic Institutions

7%

Applications of Freeform Fab. (Wohlers Report 2002)

World Freeform Fabrication2002

•10,000 FFF Machines Worldwide

•40% of all Machines in USA, 14% in Japan (3rd China, 4th Germany)

•1482 Machines Sold (1299 in 2001)

•RP Market (Products, Part/Equipment Sales, Service Bureaus)

$485 Million

•28 Original Equipment Manufacturers (11 in 1993)

•Average Cost of FFF Part = $150 ($1000 in 1993)

Source: Wohler’s Report 2003

Empirical Similitude Method: Non-Linear Dimensional AnalysisLaboratory for Freeform Fabrication

Proposal Submitted to NSF/DMI

• ESM is a process where prediction can be achieved for a system that has non-linear parameters or response variables.

• Instead of a direct mapping between a model and product, two intermediate specimens (model and product specimens) are used to capture the geometric and material property differences.

• The product of the two matrices describing the material and property variations define the product performance.

• The evaluation is hence empirical compared to the traditional similitude method, where the prediction is purely dimensional in nature.

xp = S' xm

= F' xps

S

Model SpecimenProduct Specimen

Model Product

S'

F F'

xms xps = S xms

xm = F xms

Excessive surface melting removes the original roughness but induces frozen ripples caused by surface tension gradient in the liquid.

Results indicate that Laser Polishing is a rapid and promising

finishing technique for indirect-SLS metal

parts.

ONR N00014-00-1-0334, “Surface Engineering for Solid Freeform Fabrication Processes”

Surface Shallow Melting (SSM)

Surface Over Melt (SOM)

Melting of surface apexes reduces roughness Ra values by spreading of the melt over surface valleys driven by capillary pressure.

Laser Induced Surface Polishing

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

0.5 1.5 2.5 3.5 4.5

Traveling Speed (mm/s)

Ra(

m m)

NSF Grant Number: DMI- 0200283Direct Write of Novel Optical Components

•Research Objectives: •Significant Results:

•Approach

•Graphic:

•Broader Impact:

The development of a novel manufacturing process for the direct-write of sol-gel thin films for optical components.

Silica-based thin films were deposited on silicon, quartz, and borosilicate wafers. Samples were scanned using infrared and ultraviolet lasers.

Characterization of samples was done using multiple angle ellipsometry, atomic force microscopy, and scanning electron microscopy.

To rapidly prototype optical components on standard materials.

Achieve function integration in single wafers.

Initial characterization of fluence levels (power and scan velocity) required to produce smooth tracks.

Initial test with IR laser

Scanned with UV laser at high pulse rate

LENS™ is a Means of Directly Fabricating and Repairing Parts

Design BuildPart

Parts are built line by line,layer by layer

Direct metaldeposition

Nd YAG Laser Powder Nozzles

Substrate Motion

Focus PointMolten Pool

Clint Atwood, Sandia Natl Labs

LENS Process Maps

Jack Beuth, Carnegie Mellon University

Nylon-6 Tissue Engineering Scaffolds

Suman Das, University of Michigan

Volumetric Bone micro-CT Data

Scaled Replica (SLS)

Pre-Operative Planning and Surgical Rehearsal

Denis Cormier, North Carolina State University

RTV Molded Parts Using CT Scan Data (SLA)

Precision Droplet Manufacturing

M. Orme, University of California at Irvine

Powder Deposition

Suman Das, University of Michigan

Additive/Subtractive Manufacturing

Rado Kovacevic, Southern Methodist University

Additive/Subtractive Manufacturing

Aeromet Corporation, Eden Prairie MN

Additive/Subtractive Manufacturing

Jyoti Mazumder, University of MichiganH13 Tool Steel

Direct Metal Deposition

Negative CTE Specimen

H13 tool steel with copper chill block and conformal coating

Laser Drilled Hole in AI-SIC Composite

Selective Inhibition of Sintering

B. Khoshnevis, University of Southern California

3D Printing of Ceramics

E. Sachs and M. Cima, Massachusetts Institute of Technology

Electrophotographic Printing

A.V. Kumar, University of Florida, Gainesville

Micromirror Stereolithography

Xiaochun Li, University of Wisconsin-Madison

Conclusions•US Research in Additive/Subtractive Manufacturing is diverse and advanced

•US Research in Additive/Subtractive Manufacturing represents only a piece of the total picture worldwide

•Exchange of Research Progress with Prominent European Additive/Subtractive Manufacturing Sites will:

advance the technology

enhance our understanding

improve research productivity