(Hardness Testing, Knoop Hardness, Vickers Hardness)

Vickers and Micro Vickers hardness measurements through microindentation tests.

Typical Experimental Results:

microindent1

Vickers indent made on a polycarbonate plate

microindent2

Vickers indent for hardness measurement of stainless steel plate

Vickers Hardness Measurement Results, HV1 (kgf/mm2)

Test SS430 Brass Si3N4
1 166.82 217.83 2189.97
2 163.74 221.46 2162.53
3 161.39 225.20 2305.83
4 161.56 205.20 2006.75
5 161.48 217.65 2040.34
Average 163.00 217.47 2141.08
Standard Deviation 2.35 6.73 120.61

 

Applications:

 Ceramics  Coatings  Composite Materials
 Decorative Coatings  Hardness  Knoop Hardness
 Metels  Micro Hardness  Micro Vickers Hardness
 Minerals  Steel, Cast Iron, Alloys  Surface Modification Layers
 Surface Treatment  Super Facial Hardness  Thermal Barrier Coatings
 Thin Films  Vickers Hardness  Wear Resistant Coatings

 

For more information please read our application notes:
Vickers Hardness Testing of Metallic and Ceramic Materials

 

Instruments: The Micro-Combi Indentation and Scratch Tester

instrument

Key Specifications:

Max Load up to 30 N
Load Resolution 0.3 mN
Max Depth 1 mm
Depth Resolution 0.3 nm
Max Scratch Length 120 mm
Scratch Speed 0.4-600 mm/min

 

Vickers Hardness Testing of Metallic and Ceramic Materials

 

The Vickers hardness test was developed in 1924 as a method for determining a material’s hardness regardless of an indenter’s size. It can be used for most materials, irrespective of hardness, and has one of the widest scales among hardness tests. The test is governed by ASTM standard E384 for loads ranging from 1 gf to 120 kgf. A typical Vickers hardness indentation can be seen in Figure 1.

 

AppNote-70

 

The Vickers hardness test is performed by pressing a diamond indenter tip in the form of a square-based pyramid into the sample at a specific load and then measuring the diagonal distances of the square indent that is created. The Vickers Hardness value, HV, is obtained via Equation 1,

 

AppNote-71

 

where F is the indenting force in kgf and d is the average diagonal distance of the indentation in millimeters. The standard notation for reporting is HV followed by a number representing the indentation load in kgf. For example, 20 HV8 indicates a Vickers hardness value of 20 kgf/mm2 under a load of 8 kgf. Different indentation loads are selected depending on the thickness and volume of the sample that will be indented on.

 

Vickers hardness testing is typically performed on samples that are too small or too thin to allow for testing using a different method. Stainless steel alloy 430 is frequently used as a thin protective liner for equipment used in moderately corrosive environments such as dishwashers, chemical processing equipment, heat exchangers, etc. As such, Vickers hardness testing is an appropriate method for testing SS430’s mechanical properties in many applications. Vickers hardness data for fully annealed SS430 obtained using a CSM Micro Indentation and Scratch Combi Tester (CSM Instruments, Switzerland) is given in Table 1.

 

AppNote-72

 

Vickers hardness testing is also frequently used to characterize ceramic materials. Silicon nitride, Si3N4, is an engineering ceramic that is prized for its hardness, low coefficient of thermal expansion, superior wear resistance and corrosion resistance. Since there are several different methods of processing Si3N4, a Vickers hardness test can yield valuable information regarding how the material was processed and its resulting properties. Vickers hardness data for Si3N4 obtained using a CSM Micro Indentation and Scratch Combi Tester is given in Table 2.

 

AppNote-73

 

 

ASTM Number Title Website Link
E384-11e1 Standard Test Method for Knoop and Vickers Hardness of Materials Link
B933-14 Standard Test Method for Microindentation Hardness of Powder Metallurgy (PM) Materials Link
F2328-14 Standard Test Method for Determining Decarburization and Carburization in Hardened and Tempered Threaded Steel Bolts, Screws, Studs, and Nuts Link
C1327-15 Standard Test Method for Vickers Indentation Hardness of Advanced Ceramics Link
E1077-14 Standard Test Methods for Estimating the Depth of Decarburization of Steel Specimens Link

 

ISO Number Title Website Link
22826 Destructive tests on welds in metallic materials– Hardness testing of narrow joints welded by laser and electron beam (Vickers and Knoop hardness tests) Link
6507 Metallic materials– Vickers hardness test Link
14705 Fine ceramics (advanced ceramics, advanced technical ceramics)– Test method for hardness of monolithic ceramics at room temperature Link
14271 Resistance welding– Vickers hardness testing (low-force and microhardness) of resistance spot, projection, and seam welds Link
4498 Sintered metal materials, excluding hardmetals– Determination of apparent hardness and microhardness Link
3878 Hardmetals– Vickers hardness test Link
9015 Destructive tests on welds in metallic materials– Hardness testing Link
14577 Metallic materials– Instrumented indentation test for hardness and materials parameters Link