M3-2S Special Session 19th IFHTSE Congress

Virtual test for rapid evaluation

of engineered surface coatingsDr Simon Leefe (Wilde Analysis Ltd)

Dr Pan Zhang, Dr Daniel Balint, Prof Jianguo Lin (Imperial College)

M3-2S Special Session 19th IFHTSE Congress

Overview

• Rationale and benefits

• “Virtual test” workflow

• What’s going on under the hood?

• Illustration

• Summary

• Acknowledgement

M3-2S Special Session 19th IFHTSE Congress

Rationale and Benefits

Performance demands• Machine power density increase

• Weight decrease

Industrial drivers

Increased demand on machine elements• Increased load bearing capacity

• Better tribological performance

Innovation in surface engineering• Multi-layered systems

• Nano-structured

• etc

M3-2S Special Session 19th IFHTSE Congress

Rationale and Benefits

Identify candidate• Has worked before

• Some potential

Microindentation tests• Prepare samples

• Conduct tests

Load-bearing / tribo test• Prepare samples

• Conduct tests

Design / selection of coating

systems

Functional / endurance test

Pre-screen

Rank shortlist

Evaluate

performance

• Consider more

candidates

• Propose completely new

systems

• No lead time on

specimen procurement

• Simulations can run 24/7

• Understand route to

failure

• Inform surface system

design

“Virtual tests”

M3-2S Special Session 19th IFHTSE Congress

Approach

• Select “virtual test” type

• Micro-indentation

• Load bearing

• Machining application

• Specify test parameters

• Set off simulation

• Inspect results tailored to end-user requirements

M3-2S Special Session 19th IFHTSE Congress

What‟s going on under the hood?

• “Run” button kicks off DEFORMTM simulation

• Leading edge Finite Element Analysis program

• Usually GUI driven but can be driven by text files

• Here, uses text files generated by “virtual test” GUI

• Extensive set of user subroutines from M3-2S project to implement

damage model in coating layers

• DEFORM generates results

• Results normally post-processed visually in DEFORM GUI

• Here, specific repeatable set of results generated automatically in text

format

• Virtual test GUI displays application-specific results to user

• DEFORM post-processing functionality also available

M3-2S Special Session 19th IFHTSE Congress

Start-up screen

M3-2S Special Session 19th IFHTSE Congress

Indentation test set-up

Define coating

layers (expandable

M3-2S library)

Define substrate from

DEFORM library and

(optionally) depth of

hardened layer

Define test

parameters

M3-2S Special Session 19th IFHTSE Congress

Start-up screen: select load-bearing test

M3-2S Special Session 19th IFHTSE Congress

Load-bearing test set-up

Set-up

identical, but

solution is plane

strain, not

axisymmetric

Substrate library

from drop-down

(small subset of

DEFORM library

materials)

M3-2S Special Session 19th IFHTSE Congress

View layers (to scale)

M3-2S Special Session 19th IFHTSE Congress

Generate mesh (and view)

Mesh settings are

generated automatically

from built-in geometry-

based rules, to provide

optimum trade-off between

speed and accuracy

M3-2S Special Session 19th IFHTSE Congress

Simulation in progress

Progress reported

DEFORM solver info

echoed to screen

Yes, there IS a

„stop‟ button!

M3-2S Special Session 19th IFHTSE Congress

Results: progression of damage

Location and

instant of

initiation of

failure

Extent of damage

and instant of

surface failure

M3-2S Special Session 19th IFHTSE Congress

Advanced post-processing

Full functionality of

DEFORM post-

processor is available to

more advanced users

M3-2S Special Session 19th IFHTSE Congress

Some DEFORM output

Damage

contours

Force-

displacement

curve

M3-2S Special Session 19th IFHTSE Congress

Start-up screen: machining application

2-D simplified

representation

(for quick

comparative

results)

M3-2S Special Session 19th IFHTSE Congress

Machining set-up

Similar approach

to surface system

definition

Workpiece material

Tool tip geometry

Cutting parameters

M3-2S Special Session 19th IFHTSE Congress

Cutting - mesh

M3-2S Special Session 19th IFHTSE Congress

Load-bearing and cutting

• Simulation and results display similar to indentation

• Cutting also provides order-of-magnitude estimate of

tool wear rate for comparative purposes

M3-2S Special Session 19th IFHTSE Congress

Summary

• Simple-to-use “virtual test” tool

• Aids coating system selection and comparative

evaluation

• Quicker lead time than physical tests• Rapidly screen out weak candidate systems

• Quickly identify reduced shortlist for physical tests

• Brings state-of-the-art DEFORM finite element

simulation to non-expert users

• Incorporates leading-edge research into surface

coating damage via validated models

• Provides insights into initiation and progression of

failure not available from physical tests

• Allows exploration of completely new surface systems

M3-2S Special Session 19th IFHTSE Congress

Acknowledgement

The authors thank the European Commission for their

support on the FP7 project “Multiscale Modelling for

Multilayered Surface Systems (M3-2S)”, Grant No: CP-

FP 213600-2 M3-2Sion