SmartManufacturingSeries.com

Electrochemical Additive Manufacturing

Murali SundaramAssociate Professor of Mechanical  Engineering

Secondary  Faculty, Materials ProgramDirector, Micro and Nano Manufacturing  LaboratoryDepartment  of Mechanical  and Materials Engineering 

University of Cincinnati, Cincinnati, OH

Localized Electrochemical DepositionAdditive Manufacturing

CAD File Manufactured Part

What is ECAM?• Electrochemical Additive Manufacturing (ECAM) is the

combination of localized electrodeposition and additive manufacturing principles to produce a novel additive manufacturing process with many advantages over conventional AM.

[U.S. Patent App. No. 15/235,460]

100 μm

2 mm

Localized Electrochemical Deposition• Similar to electroplating• A micro tool is used to create a

localized deposit• Aqueous metal is reduced to

solid deposit • Example:

++ −→ ( )

PublicationSundaram, M., A. B. Kamaraj, and V. S. Kumar. "Mask-less electrochemical additive manufacturing: a feasibility study." Journal of Manufacturing Science and Engineering 137.2 (2015): 021006.

CAD-CAM Integration• The entire system was designed and built in-house at UCMAN Lab

Process Control• The current passing

through the cell is monitored

• A short circuit indicates that the deposit has grown to the tool

• When this feedback is combined with 3-axis motion, deposition of 3D parts is achieved

(+)

Tool

Cathode (‐)

(+)

Tool

Z

XY

Supporting Plate

3D Stepper Motor Stage

Substrate

Applied Tool Voltage

Current Feedback

Tool

Electrolyte Tank

100 Ω

• 3-D Printing (3DP) : Powder or liquid resin, deposited in layers. Cured with UV or heat.

• Fused Deposition Modeling (FDM) : Nozzle layers molten polymer onto a support structure.

• Stereolithography (SLA): Convert liquid plastic resin/composites into solids using light

• Selective Laser Sintering/Melting (SLS): Fuses powdered material using energy beam

• Electrochemical Additive Manufacturing (ECAM): Electrochemically deposits 3D metal shapes layer-by-layer or voxel-by-voxel at room temperature

Feature/Process 3DP FDM SLA SLS ECAM

Metal printing Support Structure Stress Post processing <1 Micron Resolution

Feature/Process 3DP FDM SLA SLS

Metal printing Support Structure Stress Post processing <1 Micron Resolution

Why ECAM? ECAM can make parts from 

liquid, solid, or powder source. ECAM can make solid parts at 

macro, micro, or nano scales.

ECAM can make solid metal parts at room temperature

ECAM can built in any direction!

Ongoing ECAM Studies

Size Scalability

Micro Repair

Engineered Porosity

Strength and

Hardness

Residual Stress

Multi Material

DepositionECAM

Modeling and

Simulation

ECAM

Engineered porosity

High strength

parts

Low residual stress

No support structures

Multi‐material deposition

Micro Repair

Macro to Nano Scale

Support Structureless Manufacturing• Support structures in AM pose

many cons: extra material cost time, labor, and risk of damage to the part

• Additionally, at the small scale, support stuctures may not even be feasible

• Therefore, we have established a method of determining the correct tool path for ECAM using an example voxelized part

1

24 3

5

Support Structureless ManufacturingStep 1:Detection of supported vs. unsupported voxels

Reference Plane

Scan Direction (Normal to Plane)

Scanning for unsupported voxels

2D projection of unsupported voxels and detection of separate bodies

Detection of build orientation

Support Structureless ManufacturingStep 2:The plane manufacturing order is sequenced according to the build direction

Segment

Build Direction

Level Build Order

In  build directionPlanes

p1 …

Sublevel

p2 p3 p4 pn

Support Structureless ManufacturingStep 3:The row manufacturing order is sequenced in alternating directions from row-to-row and plane-to-plane

Rows

Sublevel

…r3

rn

r2r1

Level

Plane

Build Order

Alternates by plane

…r3

rn

r2r1

r2r3

r1

…rn

…r3

rn

r2r1

Support Structureless ManufacturingStep 4:The voxels are sequenced in alternating order by row

Level

Row Voxels

Sublevel Build Order

Alternates by row

Support Structureless Manufacturing• The allowable field of voxels for tool motion was found• The transition path from one segment to another was

madePr ( ,  ,  )

,  , 

Retract from last point on current 

segment

Approach to first point on next segment

1 to 2 2 to 3 3 to 4 4 to 5

3DX‐Y

Y‐Z

X‐Z

View

Support Structureless Manufacturing• Sequence of resulting tool

paths from segment to segment

Segment 1 to 2 Segment 2 to 3 Segment 3 to 4 Segment 4 to 5

Retract pathApproach  path

Legend

Built voxels

Transition path

Final Tool Path

Support Structureless Manufacturing

PublicationBrant, Anne, and Murali Sundaram. "A Novel Electrochemical Micro Additive Manufacturing Method of Overhanging Metal Parts without Reliance on Support Structures." Procedia Manufacturing (2016): Vol 5, pp 928-943. DOI: 10.1016/j.promfg.2016.08.081

ECAM

No support structures!

Conventional AM

Support structures

Engineered Porosity• ECAM allows for controlled porosity

of output parts• Advantages include

• Increased surface area• Lower weight• Higher strength to weight ratio

• Applications include:• Chemical – Catalyst and reaction

substrates• Biomedical – Cell adhesion; implants• Energy – Batteries and Solar cell

Porous part

Pore

Porous Implant for Hip 

Replacement [Hong, Cai, 2016]

[Pikul, J. H, 2013]

Porous Electrodes for Micro‐Batteries

Engineered Porosity• Two types of porosity, and

their causes, in the ECAM process

• Macro porosity: • irregularities in part

• Micro porosity: • hydride and bubble

generation during the electrochemical process

Platinum Electrode (+)

Brass Plate (‐)

Ni (Solid Nodules with Pores)

: 2 2 ( )  2( ) + 4 +( ) + 4 −

Cathode:  ++ −→ ( )

Oxygen Bubbles

Dissolved Nickel Salt Bath, Ni2+

Animation of porosity generation in pillar deposition

Engineered Porosity• SEM images were used to quantify volume and porosity for calculations

Porosity

Volume

Engineered Porosity

• P = Porosity percentage• VP = Volume of Pores

• calculated as the difference between the total part volume estimated from CAD model of the part and the VS

• VS = Volume of Solid• calculated from the mass of the part

and density of nickel

100)(

PS

P

VVVPPorosity

• Porosity was estimated using the following equation:

Engineered Porosity• Findings:

• Porosity between 20% – 75% achieved• Voltage and duty cycle are the primary input

parameters that influence porosity

Pore size distributionEffect of voltage and

duty cycle on porosity

Part Integrity (regular vs. irregular)

Surface Texture (rough vs. smooth)

Publication:A. B. Kamaraj, H. Shrestha, E.Speckand Sundaram, M. (2017). “Experimental study on the porosity of electrochemical nickel deposits.” ProcediaManufacturing ProcediaManufacturing 10C pp.478-485 DOI: 10.1016/ j.promfg.2017.07.032.

Strength and Hardness• The electrochemical deposition procedure was

modified to incorporate a copper powder with nickel binder

• Binding strength of the sample influences the yield strength of the electrochemically bound part. A CSM Nanoindentation tester (NHT) was

used to carry out the tests. The tester gave a hardness value in the form

of a Vickers Hardness number (HV). The HV number was correlated to get

approximated yield strength values

M+

A‐A‐

TOOL ELECTRODE (M)  (+)

METAL SUBSTRATE  (‐)

At Tool M (s) →M+ (aq) +e‐

Horizontal Feed

VerticaFeed

ELECTROLYTE

INSULATION

M+

M+ M+

M+M+

A ‐

A ‐

Inter‐Electrode Gap

M M M M M M M M

At Layer‐in‐progress M+ (aq) +e ‐→ M↓

Completed Layers

METAL POWDER

Binder Material

CSM Nanoindentation tester

Strength and Hardness• The interelectrode gap, voltage, duty cycle,

and on-time were varied• Hardness value range: 10-100 kg/mm2

• Yield strength range: 50 – 350 MPa

Comparison of Vickers hardness values

Comparison of yield strength values

Publication: • Kumar, V.S., and Sundaram, M.M (2016). “A mathematical model for

the estimation of hardness of electrochemical deposits.” Journal of Process Mechanical Engineering. DOI: 10.1177/0954408916671973

• Kumar, V.S. and M.M. Sundaram, Experimental study of b inding copper powders by electrochemical deposition. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2015. 231(8): p. 1309-1318.

Residual Stress

ECAM Process

Applied Voltage

Pulse Period Duty Cycle

Termination Criteria

3 V

4 V

5 V

100 ns

200 ns

50%

75%

Constant time

Constant height

Residual Stress

• A full-factorial experiment of the influence of input process parameters on the output residual stress of the part was conducted.

Residual Stress• The residual

stress of ECAM fell in the kParange

• This contrasts to conventional AM methods, which have a residual stress in the Mparange

Publication: Brant, A., Kamaraj, A., and Sundaram, M.(2014). “Experimental Study of Residual Stresses Induced in Nickel Micro Structures Made by Electrochemical Deposition.” ASME International Manufacturing Science and Engineering Conference, MSEC2014.

Micro Repair

‐

+

Target Substrate

Platinum Anode

LIQUID MARBLE

Micro deposit

Cu Powder

• Liquid marble method: Encasing electrolyte in a liquid marble using copper powder

• Pick-and-place technique• Can be used for localized repair,

difficult-to-reach areas, and areas where immersing the part in an electrolyte tank is not feasible or economical

Micro Repair

‐

• Results of experimental and mathematical modeling work

Publications • Shailendar, Shiv, and Murali M. Sundaram. "A

Feasibility Study of Localized Electrochemical Deposition Using Liquid Marbles." Materials and Manufacturing Processes 31.1 (2016): 81-86.

• Shailendar, Shiv, and Murali Sundaram. "Modeling of Deposition Height in Localized Electrochemical Deposition Using Liquid Marbles." Procedia Manufacturing 5 (2016): 132-143.

Modeling and SimulationTo understand the mechanisms involved in the deposition and to study the effect of process parameters on deposition rate and part quality mathematical modeling and finite element simulations of the process was performed.

0 1 2 3 4 5 60

10

20

30

40

50

60

Applied E lec tric Potential (V)

Cur

rent

Den

sity

(A/c

m2 )

1540 mol/cm3

1000 mol/cm3

2000 mol/cm3

2500 mol/cm3

0 0.005 0.01 0.015 0.020

0.5

1

1.5

2x 10-3

Distance from subs trate ( cm)

Con

cent

ratio

n (m

ol/c

m3 )

Mathematical Model

Output Current Density vs. Input Potential

Output Concentration vs. Distance from Substrate

Finite Element Simulation

Substrate

Toolµm

µm

Surface concentration plot  at 5V and 100 µm gap for a 100 µm tool width

Ion Depletion Region

IEG for 250 µm tool = 15 µmLimiting Current Potential = 2 VRate of deposition = 1 – 5 µm/s

PublicationKamaraj, Abishek, Spenser Lewis, and Murali Sundaram. "Numerical study of localized electrochemical deposition for micro electrochemical additive manufacturing." Procedia CIRP 42 (2016): 788-792.DOI:10.1016/j.procir.2016.02.320

Nano-ScaleDeposition may not occur at intended spot due to atomic-scale processes

Simulation of ECAM ProcessLegendAnode NucleusCathode NucleusElectronNewly-added ElectronAqueous Cation

What is next?• Ongoing work involves involves deposition at the

macro scale and nano scale• The nano scale poses many new challenges

compared to the micro scale

PublicationBrant, Anne M., and Murali Sundaram. "A fundamental study of nano electrodeposition using a combined molecular dynamics and quantum mechanical electron force field approach." Procedia Manufacturing 10 (2017): 253-264.

Our ECAM research has been featured in the latest issue of MForesight's "Manufacturing Ideas to Watch" ( http://mforesight.org/2017/07/31/manufacturing-ideas-to-

watch-issue-3-july-2017/).

AcknowledgmentsFinancial support provided by the National Science

Foundation (NSF) under grant numbers CMMI –1400800 and CMMI – 1454181 is acknowledged.

Thank You!For Enquiries, Questions and Comments:

murali.sundaram@uc.edu 513-556-2791