ASTM C1624-05(2010)

Standard Test Method for Adhesion Strength and Mechanical Failure Modes of Ceramic Coatings by Quantitative Single Point Scratch Testing

SIGNIFICANCE AND USE
This test is intended to assess the mechanical integrity, failure modes, and practical adhesion strength of a specific hard ceramic coating on a given metal or ceramic substrate. The test method does not measure the fundamental “adhesion strength” of the bond between the coating and the substrate. Rather, the test method gives a quantitative engineering measurement of the practical (extrinsic) adhesion strength and damage resistance of the coating-substrate system as a function of applied normal force. The adhesion strength and damage modes depend on the complex interaction of the coating/substrate properties (hardness, fracture strength, modulus of elasticity, damage mechanisms, microstructure, flaw population, surface roughness, and so forth) and the test parameters (stylus properties and geometry, loading rate, displacement rate, and so forth).
The quantitative coating adhesion scratch test is a simple, practical, and rapid test. However, reliable and reproducible test results require careful control of the test system configuration and testing parameters, detailed analysis of the coating damage features, and appropriate characterization of the properties and morphology of the coating and the substrate of the test specimens.
The coating adhesion test has direct application across the full range of coating development, engineering, and production efforts. Measurements of the damage mechanisms in a coating as a function of applied normal forces are useful to understand material-process-property relations; quantify and qualify the mechanical response of coating-substrate systems; assess coating durability; measure production quality; and support failure analysis.
This test method is applicable to a wide range of hard ceramic coating compositionscarbides, nitrides, oxides, diamond, and diamond like carbonapplied by physical vapor deposition, chemical vapor deposition, and direct oxidation methods to metal and ceramic substrates.
Note 2—Under narrow circumsta...
SCOPE
1.1 This test method covers the determination of the practical adhesion strength and mechanical failure modes of hard (Vickers Hardness HV = 5 GPa or higher), thin (≤30 μm) ceramic coatings on metal and ceramic substrates at ambient temperatures. These ceramic coatings are commonly used for wear/abrasion resistance, oxidation protection, and functional (optical, magnetic, electronic, biological) performance improvement.
1.2 In the test method, a diamond stylus of defined geometry (Rockwell C, a conical diamond indenter with an included angle of 120° and a spherical tip radius of 200 μm) is drawn across the flat surface of a coated test specimen at a constant speed and a defined normal force (constant or progressively increasing) for a defined distance. The damage along the scratch track is microscopically assessed as a function of the applied force. Specific levels of progressive damage are associated with increasing normal stylus forces. The force level(s) which produce a specific type/level of damage in the coating are defined as a critical scratch load(s). The test method also describes the use of tangential force and acoustic emission signals as secondary test data to identify different coating damage levels.
1.3 Applicability to Coatings—This test method is applicable to a wide range of hard ceramic coating compositions: carbides, nitrides, oxides, diamond, and diamond-like carbon on ceramic and metal substrates. The test method, as defined with the 200 μm radius diamond stylus, is commonly used for coating thicknesses in the range of 0.1 to 30 μm. Test specimens generally have a planar surface for testing, but cylinder geometries can also be tested with an appropriate fixture.
1.4 Principal Limitations:
1.4.1 The test method does not measure the fundamental adhesion strength of the bond between the coating and the substrate. Rather, the test method gives an engineering measurement of the practical (extri...

General Information

• Status: Historical
• Publication Date: 30-Nov-2010
• ICS: 25.220.99 - Other treatments and coatings
• Technical Committee: C28 - Advanced Ceramics
• Drafting Committee: C28.04 - Applications

Relations

• Replaces: ASTM C1624-05 - Standard Test Method for Adhesion Strength and Mechanical Failure Modes of Ceramic Coatings by Quantitative Single Point Scratch Testing
• Effective Date: 01-Dec-2010

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C1624 − 05(Reapproved 2010)
Standard Test Method for
Adhesion Strength and Mechanical Failure Modes of
Ceramic Coatings by Quantitative Single Point Scratch
Testing
This standard is issued under the fixed designation C1624; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.4.1 The test method does not measure the fundamental
adhesion strength of the bond between the coating and the
1.1 This test method covers the determination of the prac-
substrate. Rather, the test method gives an engineering mea-
tical adhesion strength and mechanical failure modes of hard
surement of the practical (extrinsic) adhesion strength of a
(Vickers Hardness HV = 5 GPa or higher), thin (≤30 µm)
coating-substrate system, which depends on the complex
ceramic coatings on metal and ceramic substrates at ambient
interaction of the test parameters (stylus properties and
temperatures. These ceramic coatings are commonly used for
geometry,loadingrate,displacementrate,andsoforth)andthe
wear/abrasion resistance, oxidation protection, and functional
coating/substrateproperties(hardness,fracturestrength,modu-
(optical, magnetic, electronic, biological) performance im-
lus of elasticity, damage mechanisms, microstructure, flaw
provement.
population, surface roughness, and so forth).
1.2 Inthetestmethod,adiamondstylusofdefinedgeometry
1.4.2 The defined test method is not directly applicable to
(Rockwell C, a conical diamond indenter with an included
metal or polymeric coatings which fail in a ductile, plastic
angle of 120° and a spherical tip radius of 200 µm) is drawn
manner, because plastic deformation mechanisms are very
across the flat surface of a coated test specimen at a constant
different than the brittle damage modes and features observed
speed and a defined normal force (constant or progressively
inhardceramiccoatings.Thetestmethodmaybeapplicableto
increasing) for a defined distance. The damage along the
hard metal coatings which fail in a brittle mode with appro-
scratch track is microscopically assessed as a function of the
priate changes in test parameters and damage analysis proce-
applied force. Specific levels of progressive damage are
dures and criteria.
associated with increasing normal stylus forces. The force
1.4.3 The test method, as defined with the Rockwell C
level(s) which produce a specific type/level of damage in the
diamond stylus and specific normal force and rate parameters,
coatingaredefinedasacriticalscratchload(s).Thetestmethod
isnotrecommendedforverythin(<0.1µm)orthickercoatings
alsodescribestheuseoftangentialforceandacousticemission
(>30 µm). Such coatings may require different stylus
signals as secondary test data to identify different coating
geometries, loading rates, and ranges of applied normal force
damage levels.
for usable, accurate, repeatable results.
1.4.4 The values stated in SI units are to be regarded as
1.3 Applicability to Coatings—This test method is appli-
cable to a wide range of hard ceramic coating compositions: standard. No other units of measurement are included in this
standard. Test data values in SI units (newtons (N) for force
carbides, nitrides, oxides, diamond, and diamond-like carbon
on ceramic and metal substrates. The test method, as defined andmillimetres(mm)fordisplacement)aretobeconsideredas
standard and are in accordance with IEEE/ASTM SI10.
with the 200 µm radius diamond stylus, is commonly used for
coating thicknesses in the range of 0.1 to 30 µm. Test 1.4.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
specimens generally have a planar surface for testing, but
cylinder geometries can also be tested with an appropriate responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
fixture.
bility of regulatory limitations prior to use.
1.4 Principal Limitations:
1.5 Organization—The test method is organized into the
following sections:
Section
This test method is under the jurisdiction of ASTM Committee C28 on
Scope 1
Advanced Ceramics and is the direct responsibility of Subcommittee C28.04 on
Purpose and Description 1.1
Applications.
Applicability 1.3
Current edition approved Dec. 1, 2010. Published January 2011. Originally
Principal Limitations 1.4
approved in 2005. Last previous edition approved in 2005 as C1624–05. DOI:
Organization 1.5
10.1520/C1624-05R10.
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
C1624 − 05 (2010)
E4Practices for Force Verification of Testing Machines
Section
Referenced Documents 2
E18Test Methods for Rockwell Hardness of Metallic Ma-
ASTM Standards 2.1
terials
Other Standards and References 2.2
E750Practice for Characterizing Acoustic Emission Instru-
Terminology 3
Summary of Test Method 4
mentation
Significance and Use 5
E1316Terminology for Nondestructive Examinations
Test Methodology and Experimental Control 6
E1932Guide for Acoustic Emission Examination of Small
Test Overview 6.1
Test Modes 6.2
Parts
Primary and Supplementary Measurements 6.3
IEEE/ASTM SI10Standard for Use of the International
Critical Scratch Load Damage Criteria and Scratch Atlas 6.4
Experimental Factors and Variables 6.5 System of Units (SI) (The Modern Metric System)
Interferences 7
2.2 ASME Standard:
Material and Specimen Related 7.2
ASME B46.1 Surface Texture (Surface Roughness,
Test Method Related 7.3
Apparatus 8 Waviness, and Lay)
General Description 8.1
2.3 CEN Standard:
Stylus and Stylus Mounting 8.2
CEN prEN 1071-3 Advanced Technical Ceramics—
Mechanical Stage and Displacement Control 8.3
Methods of Test for Ceramic Coatings—Part 3: Determi-
Test Frame and Force Application System 8.4
Force and Displacement Sensors 8.5
nation OfAdhesiveAnd Other Mechanical Failure Modes
OpticalAnalysis and Measurement 8.6
By A Scratch Test
Data Acquisition and Recording 8.7
Acoustic Emission (Optional) 8.8
3. Terminology
Coating Adhesion Reference Specimens (Optional) 8.9
Coating Surface Profilometry (Optional) 8.10
3.1 Definitions:
Data Analysis and Output Software (Optional) 8.11
Test Specimens 9 3.1.1 acoustic emission, n—class of phenomenon in which
Specimen Requirements 9.1
elasticwavesaregeneratedbytherapidreleaseofenergyfrom
Specimen Characterization 9.2
localized sources within a material, or the transient waves so
Specimen Size 9.3
Specimen Flatness and Level 9.4 generated. E1316
Polishing (Optional) 9.5
3.1.2 adhesive failure, n—detachment and separation of a
Specimen Exposure Conditioning (Optional) 9.6
Specimen Cleaning 9.7 coating from the substrate with cracking and debonding at the
Specimen Handling and Storage 9.8
coating-substrate interface.
Calibration 10
System Calibration 10.1 3.1.3 cohesive failure, n—material damage and cracking in
Reference Specimens 10.2
the coating or in the substrate, separate and distinct from
Test Procedure 11
detachment and adhesive debonding at the coating-substrate
Calibration 11.1
Test Mode Selection 11.2
interface.
Test Planning 11.3
3.1.4 critical scratch load (L ), n—appliednormalforceat
Stylus Inspection and Cleaning 11.4 CN
Environmental Conditions 11.5
which a specific, well-defined, recognizable damage/failure
System Set-Up and Check 11.6
event occurs or is observed in the scratch test of a specific
Test Specimen Mounting 11.7
coating on a specific substrate.
Conducting the Test 11.8
Specimen Count 11.9
3.1.4.1 Discussion—The subscript N is used to identify
Invalid and Censored Data 11.10
progressive failure events. For example, L is often used to
C1
Scratch Damage Assessment 11.11
identify the first level of cohesive failure in the coating itself;
Calculations 12
Report 13
L is often used to identify first adhesive failure between the
C2
Test Identification 13.2
coating and the substrate. Multiple subscripts can be used for
Specimen Information 13.3
progressive levels of distinct damage in a specific coating-
Test Equipment and Procedure Information 13.4
Test Data and Statistics 13.5
substrate systems.
Precision and Bias 14
3.1.5 fundamental adhesion, n—summationofallinterfacial
Keywords 15
Rockwell Diamond Indenter Specifications Annex A1
intermolecular interactions between a film or coating and its
Alignment and Calibration Annex A2
substrate.
Repeatability and Reproducibility Studies Annex A3
Coating Damage Criteria and Scratch Atlas Appendix X1
3.1.6 normal force (L ), n—in a scratch test, the force
N
Experimental Variables in Scratch Adhesion Testing Appendix X2
exerted by the stylus, perpendicular to the test surface of the
Bibliography
test specimen.
2. Referenced Documents
3.1.7 practical adhesion, n—force or work required to
2.1 ASTM Standards:
remove or detach a film or coating from its substrate irrespec-
B659Guide for Measuring Thickness of Metallic and Inor-
tive of the locus of failure.
ganic Coatings
Available from American Society of Mechanical Engineers (ASME), ASME
For referenced ASTM standards, visit the ASTM website, www.astm.org, or International Headquarters, Three ParkAve., NewYork, NY10016-5990, www.as-
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM me.org.
Standards volume information, refer to the standard’s Document Summary page on Available from European Committee for Standardization (CEN), 36 rue de
the ASTM website. Stassart, B–1050 Brussels, www.cenorm.be.
C1624 − 05 (2010)
3.1.7.1 Discussion—“Practical adhesion” is a test concept
which uses various engineering coating adhesion test methods
to obtain a quantitative, reproducible adhesion measurement
which can be related to the functional performance of the
coating. The practical adhesion is an extrinsic property which
depends on the complex interaction of coating/substrate prop-
erties and characteristics with the specific test parameters.
3.1.8 stylus drag coeffıcient, n—in scratch testing, the di-
mensionless ratio of the tangential force to the normal force
applied to the stylus at a specific point in the scratch test.
3.1.8.1 Discussion—The term stylus drag coefficient is pre-
ferred to the more common term scratch coefficient of friction
(SCF). The tangential force is primarily a measure of the
perpendicular force required to plow the indenter through the
coating, rather than to slide it on the surface (sliding friction is
FIG. 2 Schematic Example of Progressive Damage in Scratch
arelativelyminorcontributiontothemeasuredtangentialforce
Track in a Progressive Load Scratch Test
unless penetration is very small and surface properties domi-
4.2 The specific levels and types of progressive damage in
nate). Thus the term friction coefficient is not appropriate for
the scratch track are assessed and associated with the applied
these stylus scratch tests. The SCF term is too easily misun-
normal stylus forces. The normal force which produces a
derstood or misused as a measurement of sliding friction.
specific, defined, reproducible type/level of damage is defined
3.1.9 tangential force (L ), n—force that opposes the rela-
T
as a critical scratch load (L ). For a given coating-substrate
C
tive motion between a moving stylus and the surface that is
system, one or more different critical scratch loads (L ) can
CN
beingscratchedbythestylusandwhichisperpendiculartothe
be defined for progressive levels of defined coating damage.
normal force exerted by the stylus (also called the friction
4.3 Coating damage is assessed by optical microscopy or
force, drag force, or the scratching force).
scanning electron microscopy, or both, during or after the
scratchtestisdone.Thetangentialforceandacousticemission
4. Summary of Test Method
signals can also be measured and recorded during the scratch
4.1 This test consists of producing and assessing controlled
test process and used as supplementary test data to identify
damageinahardceramiccoatingbysinglepointscratchaction
different coating damage levels. In commercial instruments,
(seeFig.1).Thescratchisdevelopedonacoatedtestspecimen
computerized electronic systems are commonly used to apply,
by drawing a diamond stylus of defined geometry and tip size
control, measure, and record the force signals and acoustic
(Rockwell C, 200 µm radius) across the flat surface of the
emissionsignalsandtocontrolthestylus-specimenmovement.
specimen at a constant speed and a controlled and measured
4.4 The two primary modes of scratch adhesion testing are
normal force (constant or progressively increasing). With
constant load and progressive load. In constant load (CL)
increasing applied normal force, the stylus produces progres-
scratch testing, the normal force on the stylus is maintained at
sive mechanical damage in the coating and the substrate
a constant level as the stylus moves in relation to the test
through the complex combination of elastic/plastic indentation
specimen surface. Sequential scratch tests are done at increas-
stresses, frictional forces, and residual internal stresses in the
ing force increments to determine the critical scratch load for
coating/substrate system (Fig. 2).
a given damage level.
NOTE 1—Test systems may have either a movable stage or a movable
stylus with the alternate component in a fixed position.
4.5 In progressive load (PL) scratch tests, the applied stylus
force is linearly increased to a defined maximum force as the
stylus moves in relation to the test specimen surface.
4.6 The critical scratch loads at which a defined coating
failure event occurs depend on a complex interaction of
coating-substrate properties and test parameters/conditions. It
is the purpose of this test standard to: (1) describe and define
the test equipment and procedures and the major and minor
coating-substrate properties which have to be controlled,
measured, and understood to produce reliable, comparable
coating adhesion test data, and (2) define a report format that
will provide complete and accurate test data.
5. Significance and Use
5.1 This test is intended to assess the mechanical integrity,
FIG. 1 Test Method Schematic failure modes, and practical adhesion strength of a specific
C1624 − 05 (2010)
hard ceramic coating on a given metal or ceramic substrate. 5.8 The test is commonly conducted under unlubricated
The test method does not measure the fundamental “adhesion conditionsandatroomtemperature.However,itisfeasibleand
strength” of the bond between the coating and the substrate. possible to modify the test equipment
...