Pencil Hardness
Measuring Coating Mechanical Properties CTT 2019 Rahul Nair
Fischer Technology, Inc. 2018 1 Coating Mechanical Properties Characterization
Nanoindentation Progressive Load Scratch
Fischer Technology, Inc. 2018 2 Characterizing Surfaces
Treated surfaces
Coatings and Thin Films
Composites
Fischer Technology, Inc. 2018 3 Coating Mechanical Properties Characterization
Fischer Technology, Inc. 2018 4 Coating Mechanical Properties Characterization
H a r d n e s s I C r e e p I E l a s t i c i t y I U n i a x i a l M e c h a n i c a l R e s p o n s e I Te n s i l e S t r e n g t h and Te n s i l e S t r e s s I S t i f f n e s s in Te n s i o n - Yo u n g ’ s M o d u l u s I T h e P o i s s o n E f f e c t I S h e a r i n g S t r e s s e s and S t r a i n s S t r e s s - S t r a i n C u r v e s Thermodynamics of M e c h a n i c a l R e s p o n s e I E n t h a l p i c R e s p o n s e I E n t r o p i c R e s p o n s e I Viscoelasticity I S t i f f n e s s I K i n e m a t i c s : the S t r a i n – Displacement R e l a t i o n s I Equilibrium : the S t r e s s R e l a t i o n s I Transformation of S t r e s s e s and S t r a i n s Constitutive I Y i e l d and P l a s t i c F l o w I M u l t i a x i a l S t r e s s S t a t e s I E f f e c t of Hydrostatic P r e s s u r e I E f f e c t of Rate and Temperature I C o n t i n u u m P l a s t i c i t y I T h e Dislocation B a s i s of Y i e l d and C r e e p K i n e t i c s of C r e e p in Crystalline M a t e r i a l s I F r a c t u r e I A t o m i s t i c s of C r e e p R u p t u r e I F r a c t u r e M e c h a n i c s - the E n e r g y - B a l a n c e A p p r o a c h I the S t r e s s I n t e n s i t y A p p r o a c h I F a t i g u e
Fischer Technology, Inc. 2018 5 Characterizing Surfaces
Mechanical Properties of these coatings is greatly influenced by several factors
i. Chemistry
ii. Deposition Technique
iii. Curing Procedure
iv. Aging and Weathering- Thermal, Oxidative and UV
v. Environmental Conditions- Temperature and Humidity
Fischer Technology, Inc. 2018 6 Traditional Hardness Testing
Hardness – resistance to penetration of a hard indenter
Fischer Technology, Inc. 2018 7 Traditional Hardness Testing- Mohs Scale
The ability of one solid to scratch another or to be scratched by another solid
Austrian mineralogist Friedrich Moh, 1812
Fischer Technology, Inc. 2018 References -1. http://www.hautehorlogerie.org/en/glossary/mohs-scale-187/ 8 Traditional Hardness Testing- Pencil Hardness
These alternate techniques are inexpensive Pencil hardness Handheld Hardness Testers Scratch Testers for Scratch Hardness
BUT….
Fischer Technology, Inc. 2018 9 Traditional Hardness Testing- Pencil Hardness
i. Study to check the variability in the standard Pencils used in Pencil hardness testing
ii. Our nanoindentation tester used to measure Martens Hardness of standard Pencils
iii. At higher hardness range there is inconsistency of the pencil hardness of the standard pencils
iv. Even at lower hardness levels pencil hardness of standard pencils overlaps
v. Additionally, more uncertainty introduced by influence from user
Fischer Technology, Inc. 2018 10 Traditional Hardness Testing- Brinell
Apply fixed load & Optical measure of the residual print area
- Swedish engineer Johan August Brinell in 1900
Fischer Technology, Inc. 2018 References -1. http://www.precisiontestingequip.com/p1_02_3.html 2. http://en.wikipedia.org/wiki/Brinell_scale 11 Traditional Hardness Testing- Rockwell
Apply fixed pre-load, Apply fixed load & Penetration depth measurement - Patented by Hugh M. Rockwell and Stanley P. Rockwell from CT in 1914
Fischer Technology, Inc. 2018 References -1. http://www.wilson-hardness.com/Products/RockwellTesters.aspx 12 Traditional Hardness Testing- Vickers & Knoop
Apply fixed load & Optical measure of the residual print area
- 1921 by Robert L. Smith and George E. Sandland at Vickers Ltd in Britain
Optical measurement Application of a fixed load of the indentation
Fischer Technology, Inc. 2018 References -1. http://www.instron.us/wa/applications/test_types/hardness/vickers.aspx 13 Traditional Testing- E-Modulus (Young’s modulus)
ideal elastic behaviour of solid states : Hooke‘s law (1676) ideal spring : tensile test (e.g. steel) F = k.x F stress : A k: spring constant
k l F (l l0 ) *100% 0 strain : l0 D k 2Dl Dl *100% l F l x 2 0 F E const. matter constant E [Nmm-2] (Young’s Modulus, 1807)
Fischer Technology, Inc. 2018 14 Limitations of Traditional Hardness Testing
• In applications where treated surfaces, coatings, thin films or composites are tested • shows substrate influence • indent may be too small to observe with a microscope • (Soft) imprint on elastic materials may be too small to observe with microscope
• Testing big volumes of material can be time consuming
• Only hardness can be calculated Coating Large Stress Base Material Field
Fischer Technology, Inc. 2018 15 Principles of Nanoindentation
. Apply a load (F) incrementally until a Force Actuator maximum is reached . Result: h=f(F,t) F . Martens hardness HM is calculated as a Displacement Sensor function of depth . The load decrease curve is used for the calculation of material parameters
Indentation Modulus Eit, Indentation Hardness Hit Indenter . ISO14577 and ASTM E2546 Test Specimen
Fischer Technology, Inc. 2018 16 Principles of Nanoindentation
Apply a load (F) incrementally until a maximum is reached Result: h=f(F,t) Martens hardness HM is calculated as a function of depth The load decrease curve is used for the calculation of material parameters Indentation h=f(F,t) Modulus Eit, Indentation Hardness Hit
Fischer Technology, Inc. 2018 17 Principles of Nanoindentation
ideal elastic ideal plastic (rubber, spring) (modeling clay)
h h elastic + plastic
h F F
F
Fischer Technology, Inc. 2018 18 Indentation hardness : Calculation of Vicker Hardness
Fmax Indentation Creep H IT ( HV H IT *0.0945 ) AP (hc ) h2 h1 CIT1 * 100 h2
Indentation modulus Unloading 2 1s hmax Martens hardness EIT 2 1 1i Er Ei Loading
h, h, indentation depth S Er Indentation Recovery 2 AP (hc ) Fischer Technology,h2 Inc. 2018h1 CIT2 * 100 F, applied force (load) h2 19 Dynamic Nanoindentation
Storage and loss moduli, loss tangent
Fischer Technology, Inc. 2018 20 Advantages of Nanoindentation
. Wide variety of Materials: Applies low load - Measure shallow depths . No optical measurement: no influence of the user . The instrumented indentation test yields more information than classical hardness measurements
. Indentation Hardness HIT . Martens Hardness . Indentation Modulus EIT . Work Done- Elastic and Plastic . Creep CIT . Vickers and Knoop Hardness 10% . Fracture Toughness . Pop-in and Pop-out . Storage and Loss moduli . Glass Transition
. Mechanical Properties Mapping
Fischer Technology, Inc. 2018 21 Nanoindenter Form Factor – Base Instrument
Reliable, cost-effective, user-friendly instrument to measure hardness, elastic modulus, creep and much more of coatings and bulk material
Automated surface Ample load and depth range; detection for higher broad range of applications productivity Minimal sample preparation due to open layout
Solid granite base with specialized vibration Compact design makes the isolation silicone feet to HM2000S an ideal tool for reduce noise all environments
Fischer Technology, Inc. 2018 22 Nanoindenter Form Factor – Fully Equipped
Feature-packed, user-friendly instrument to measure hardness, elastic modulus, creep and much more of coatings and bulk material
Minimal sample preparation Motorized z-axis and due to large working area fully-automated surface and open layout detection for higher productivity
Enhanced high resolution optical system with autofocus and Same measuring head as multiple objective turret HM2000 S Measure on smallest structures, cross-sections Custom granite structure with high precision for enhanced frame programmable xy-table stiffness and low noise
Fischer Technology, Inc. 2018 23 Factors that effect Nanoindentation
Advantage Cone . Protects Indenters & Speeds up Indentation . Software algorithms to auto detect surface
Fischer Technology, Inc. 2018 24 Factors that effect Nanoindentation
Advantage Cone . Low Thermal Drift . Low Frame Compliance
Fischer Technology, Inc. 2018 25 Base Instrument Application: Automotive Paint and Clear Coats Measurement of two 80 µm thick 2K automotive repair paints • Max. indentation depth < 6.5 µm
2K automotive repair HM E IT paints Samples N/mm² GPa
Mean value Sample A 42.9 1.4 Sample B 143.0 3.1 Standard deviation Sample A 1.2 0.1 Sample B 5.6 0.1
Fischer Technology, Inc. 2018 26 Base Instrument Application: Wood Coating Measurement of seven 100 µm thick coatings
Fischer Technology, Inc. 2018 27 Base Instrument Application: Wood Coating
Fischer Technology, Inc. 2018 28 Base Instrument Application: Wood Coating
Similar Coating but different
wood substrate Hardness(HM)
Depth (µm)
Fischer Technology, Inc. 2018 29 Fully Equipped Instrument- Motorized XYZ & Microscope Application: Conformal Coatings- Cross-linking correlation Two-component conformal coatings are often used to minimize current leakage on PCBs and as protection against humidity and other environmental factors
HM[N/mm²] Depth [µm] 10 % over cross-linked 5 % over cross-linked Optimally cross-linked 5 % under cross-linked 10 % under cross-linked
Depth [µm] Time [s] Martens hardness Indentation Creep
Fischer Technology, Inc. 2018 30 Fully Equipped Instrument- Motorized XYZ & Microscope Application: High Polymer Coatings • Indenter – Spheroconical diamond • F =10mN, Loading Time = 10sec, F =80mN, Loading Time = 36sec
Fischer Technology, Inc. 2018 31 Fully Equipped Instrument- Motorized XYZ & Microscope Heating Stage
• Temperatures up to 200°C • Two temperature sensors (internal in the table and external to place on the sample) • Ceramic indenter and heat shield to eliminate thermal expansion in the head
Fischer Technology, Inc. 2018 32 Fully Equipped Instrument- Motorized XYZ & Microscope Application: High Temp Stage – Polymer Coatings
Polyamide PA66
• Thermal properties Increasing o Glass-transition temperature: 50 – 60 °C Temperature o Melting point: 260 °C o Max. operation temperature: 80 – 120 °C
Fischer Technology, Inc. 2018 33 Fully Equipped Instrument- Motorized XYZ & Microscope Application: High Temp Stage – Polymer Coatings
Glass-transition temperature Glass-transition temperature Creep nit
[%] CIT1 [%]
150 nit 60 20
[N/mm²] part
100 40
hardness Elastic 10
50 20 Martens Martens
50 100 150 50 100 150 Temperature [°C] Temperature [°C] • Coating thickness 100 µm Max. load 10 mN • Martens hardness shows decrease with increasing temperature • Creep and elastic behavior: extreme in the region of the glass transition temperature
Fischer Technology, Inc. 2018 34 Coating Adhesion- Traditional Techniques
Fischer Technology, Inc. 2018 35 Progressive Load Scratch Testing
Depth ASTM C1624 Sensor
Fischer Technology, Inc. 2018 36 Progressive Load Scratch Testing
Fischer Technology, Inc. 2018 37 Progressive Load Scratch Testing
Fischer Technology, Inc. 2018 38 Scratch Test- Actutors and Sensors
Minimal sample preparation Motorized Z-axis and fully- due to large working area automated surface detection for and open layout higher productivity
Optical microscope- Upto 5 objectives with DIC Mode with Polarized Measuring with load light filter system, depth and AE
Custom granite structure Programmable XY-table for enhanced frame Friction Table built in stiffness and low noise
Fischer Technology, Inc. 2018 39 Key Features
. Load . Industry leading range from 0.01 to 30N with 6uN resolution . Active Force Feedback- Capacitive Sensor . Excellent linearity of sensor Non-linearity- <= 0.02% of FSO . Most robust design- Overload protection of 500% of FSO
High overload protection protects the instrument from damage in case of a crash https://www.youtube.com/watch?v=BflgP7PIzYc
Fischer Technology, Inc. 2018 40 Key Features
. X, Y & Z Stages- BLDC motors . Almost 4 times higher torque than stepper motors . Better repeatability . Scratch Length- 100mm . Stages displacement- 200 x 50 x 100mm . Programmable for multiple scratches and samples
Faster stages combined with software that quickly acquires and compiles images results in highest productivity https://www.youtube.com/watch?v=BflgP7PIzYc
Fischer Technology, Inc. 2018 41 Key Features
. Microscope . Microscope with excellent video image as a result of high quality optics with 5x and 20x objective . Easy to resolve different failure mechanisms with DIC Mode with Polarized light filter
Optically identifying the failure is the most important for characterizing scratches- hence we chose the best optics for any scratch tester
Fischer Technology, Inc. 2018 42 Key Features
. Friction Table . Use same capacitive sensor as normal load . Very high resolution . Negligible compliance
In addition to better quality friction data, the results do not change with or without friction table. There is no loss of energy compared to LVDT based friction tables which can cause 5-15% error in data.
Fischer Technology, Inc. 2018 43 Key Features
. Depth sensor- . Pre scan and Post Scan . Range- 1600 um . Resolution- 0.2nm
Higher depth range- Test across smaller curvatures and difficult geometries without the depth signal saturating
Fischer Technology, Inc. 2018 44 Application – Paint on Steel
50µm diamond indenter LC1 LC2 LC3 S1 3.77 N 5.43 N 7.58 N
Fischer Technology, Inc. 2018 45 Application – Paint on Steel
50µm diamond indenter LC1 LC2 LC3 S1 3.77 N 5.43 N 7.58 N
Fischer Technology, Inc. 2018 46 Application – Paint on Steel
50µm diamond indenter LC1 LC2 LC3 S1 3.77 N 5.43 N 7.58 N
Fischer Technology, Inc. 2018 47 Summary
. Nanoindentation . Quantitative test for coatings on any substrate . Fundamental properties of only the coating . More than just hardness- elastic modulus, creep, etc.
. Progressive Load Scratch . Simulation of real world under controlled lab conditions . Test of the entire coating-substrate system . Measure mar, crack and chip resistance and adhesion
Fischer Technology, Inc. 2018 48 Thank you!
Visit us at Booth #74
Fischer Technology, Inc. 2018 49 Application – DLC on Steel
200µm diamond indenter LC1 LC2 LC3 S1 5.03 N 27.15 N 58.45 N
Fischer Technology, Inc. 2018 50 Application – DLC on Steel
200µm diamond indenter LC1 LC2 LC3 S1 5.03 N 27.15 N 58.45 N
Fischer Technology, Inc. 2018 51 Application – DLC on Steel
200µm diamond indenter LC1 LC2 LC3 S1 5.03 N 27.15 N 58.45 N
Fischer Technology, Inc. 2018 52 Fully Equipped Instrument- Motorized XYZ & Microscope
Application: Cross-sections Depth
Load Metallic HM E /(1-vs^2) H IT IT HV layer N/mm² GPa N/mm² X 4734.2 151.8 6961.9 657.8 s 223.9 8.8 263.6 24.9 V/% 4.7 5.8 6.0 6.0
Fischer Technology, Inc. 2018 53