Adding a Fourth

Dimension to 3-D

Printing

Zeeshan Ahmed, James A. Fedchak, Makfir Sefa, Julia Scherschligt, Nikolai Klimov and Matt Hartings

Sensor Science DivisionPhysical Measurement Laboratory

Certain equipment or materials are identified in this paper in order to specify the experimental procedure adequately. Such identification is not intended to imply endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the materials or equipment identified are necessarily the best available.

Disclaimer

• The Engineering Laboratory program is focused on material characterization, real-time control of additive manufacturing processes, qualification methodologies and system integration.

• The Material Measurement Laboratory is investigating additive manufacturing-related issues for both metals and polymers. Projects underway include studying the (nano)-mechanical properties of materials, modeling of microstructure evolution, and relationships between precursors and final product quality.

• The Physical Measurement Laboratory is studying emissive properties of materials in solid, powder, and liquid states, as well as improved techniques for real-time temperature measurements.

Additive Manufacturing at NIST

3https://www.nist.gov/topics/additive-manufacturing

• The Thermodynamic Metrology group realizes, maintains, and disseminates the national measurement standards for temperature, humidity and pressure and vacuum.

• We conduct innovative research aimed at developing novel methods for measurements of temperature, pressure, vacuum and humidity.

4

Thermodynamic Metrology Group

http://www.nist.gov/pml/div685/grp01/

Photonic Pressure Standard Photonic Thermometer

• We are exploring the use of additive manufacturing in metrology.

• Our interest is driven by the potential to conserve resources (time and money) and freedom of design that is inherent to additive manufacturing.

• There are two thrusts to our research program:

– Design of novel metrology instruments

– Fabrication of chemically active materials

• applications in gas storage and chemical sensing

Additive Manufacturing in Metrology

52 4 6 8 10

Tra

nsm

issio

n (

au)

Time (ps)

photonic crystal fiber

band pass filter

6

Can we use 3D printed metal parts in Atom-traps?

• We are developing an innovative atom-trap based Extremely High Vacuum (XHV) standard that relies on measurements of trap loss rate to realize vacuum.

• We envision the use of embedded metalized fiber optics to deliver light into the active region thus avoiding the use feedthroughs that could compromise trap environment

• Are 3D printed materials (stainless steel and Ti) suitable to XHV operation?

https://www.nist.gov/programs-projects/cold-core-technology-platform

7

Measurement System and Method

Sample chamber

RGA IG

TMP

SRGSC

V

Ceff

MC

Q - Outgassing flowA - Surface areaVsc - Volume of sample chamberCeff- effective pumping speedP - pressure (valve open)

P0 - pressure (valve closed)

• Outgassing rate

𝑞 =𝑄

𝐴𝑢𝑛𝑖𝑡(𝑃𝑎𝐿𝑠−1𝑐𝑚−2)

Rate-of-rise

𝑄 = 𝑉𝑠𝑐 ×∆𝑝𝑠𝑐

∆𝑡

Simple, robust methodNot suitable for condensable species e.g. H2O

t0 t

P0

P

open Close

Accumulation

𝑃𝑉𝑠𝑐 = 𝐶𝑒𝑓𝑓 × 0

𝑡

𝑃(𝑡) − 𝑃0 𝑑𝑡

Complicated measurement schemeBest suited for fast, time dependent outgassing processes

t0 t

P0

P

openClose

𝑄 = (𝑃 − 𝑃0)× 𝐶𝑒𝑓𝑓Robust methodLittle more complicated than ROR Need to quantify Ceff

Applicable to any gas species

Throughput

P

t0 t

P0

P

open Close

𝑃 − 𝑃0

8

Measurement Protocol

RGA IG

TMP

SRG

V

Ceff

MC

All parts of system were baked in vacuum for 15 days at 430 °C (except RGA, IG and TMP)

Assembly the system

Bake the system for 48 h at 150 °C to remove water

Measure outgassing of sample chamber (Background) using rate-of-rise method

Bake the system for 48 h at 150 °C to remove water

Measure Outgassing using rate-of rise method

Outgassing was measured at room temperature

Place sample on the sample chamber

SC

9

3-D Printed Sheets (Ti 64)

Surface area of the samplesA = 496 cm2

Volume of the sheetsV = 42.3 cm3

Surface area of the samples chamberA = 212 cm2

Volume of the sheetsV = 150 cm3

10

Density of 3D printed Ti: 3.488 to 3.948 g/mlDensity of Commercially available Ti: 4.4 to 4.9 g/ml.

3-D Printed Sheets (Ti 64)

11

𝛥𝑃

𝛥𝑡[𝑃𝑎 𝑠−1] 𝑉 [L] 𝑄 = 𝑉

𝛥𝑃

𝛥𝑡[𝑃𝑎 𝐿 𝑠−1] 𝐴 [𝑐𝑚2] 𝑞 =

𝑄

𝐴[𝑃𝑎 𝐿 𝑠−1𝑐𝑚−2]

𝑆𝐶 1.56 × 10−9 0.15 2.36 × 10−10 212.2 1.11 × 10−12

𝑆𝐶 + 𝑇𝑖 2.45 × 10−9 0.11 2.66 × 10−10 / /

𝑇𝑖 / 0.04 3.08 × 10−11 496 6.20 × 10−14

Outgassing from 3-D Printed Sheets (Ti 64)

RGA signals of pressure burstRate-of-rise data

H2 gas

FluxRate of rise Vol adj. rate of rise

12

Outgassing from Chambers

Traditional stainless steel Printed stainless steel (316 L) Printed Ti

3-D Printed Sheets (Stainless Steel)

SEM of Stainless Steel blocks

SEM of Stainless Steel chamber

Work on outgassing behavior of 3D printed stainless is currently underway. We are examining the role of starting material on the hydrogen outgassing rate of the final printed piece

Enabling a new dimension for 3D printing: Chemistry

Masterbatch

Nanoparticle

Polymer:ABS/PLA

Blend to Percentage

ExtrudeFilament

Print Shape

Altering Mechanical Properties of Feedstock Plastic

15

TiO2 quenches the native

fluorescence of ABS

http://dx.doi.org/10.1080/14686996.2016.1152879

ABS 10% MOF5

50% MOF5

10% ZIF-8

10% HKUST-1

MoF Ref: Science 2002, 295 (5554), 469-472.

MOF-ABS Composites

MOF-ABS CompositesSEM of MOF-ABS composite filament

EDX map overlayed over SEM image shows the presence of ZnOSEM of MOF-ABS composite printed piece

SEM and EDX mapping of the filament and printed piece confirm MOF crystals are dispersed through out the plastic and retain

Just the ABS

3D-Printed ABS absorbs mostly H2O from atmosphere, 0.15% wt/wt in 24 h and 0.36% wt/wt in 360 hr when in air

The water diffusion coefficient at 23 C is 8.1 X 10-8 cm2 (12% uncertainty at k=1)

While ABS can be used in UHV, it must degassed for 3 days at 100 C

http://dx.doi.org/10.1116/1.4965304

MOF-ABS Composites

19

DOI 10.17605/OSF.IO/N48ET

Degraded MOF-5 samples retain their H2 loading capacity following the blending and printing process

ZIF-8 and HKUST-1 Composites

DOI 10.17605/OSF.IO/B7NCF

ZIF-8 and HKUST-1 Composite’s Gas Storage Properties

DOI 10.17605/OSF.IO/B7NCF

• Our preliminary measurements on Ti and Stainless Steel indicate that these materials are generally compatible with vacuum operation. – Helium leaks where a major problem in printed stainless steel chamber (316 L) and

points to a need to better develop the fabrication process

• We have demonstrated that MOF impregnated ABS can selectively store and release gas molecules.

Summary

22

Acknowledgments:

• Peter Liacourous (Additive Manufacturing)

• Nathan Castro (Biomedical Metrology)

Collaborators

• Matt Skorski

• Megan Chanel

• Michael Bible

Students