Hardness tester WPM

Posted by Vico Casting Export Company Limited at 30/12/2019

PRINCIPLES OF MATERIALS HARDWARE MEASUREMENTS

BRINELL HARDNESS TEST (HB)

Principles:

- Measuring spot is made from ball-shaped tip

- Load: < 3000 kg

- Check the measuring tip with the optical system

 

 

 

 

Brinell scale with factors:

Different L/D2

 

Ball Dlam (mm)                      Load (Kp)

 

Applications:  
      10           3000        1000          500          250

Used for large, not too accurate parts,  such as castings and forgings

-  Not used for very hard materials, thin sheets, curved surfaces

   
       5             750          250          125          62.5
      2.5          187.5        62.5         31.2         15.6
    RATIO      HR30        HB10        HB5        HB2.5

 

Advantages:

- Wide measuring range

- Comparable with other loads (with a fixed L/D2 factor)

- Less sensitive to test surface quality

- Relative with tensile strength

 

Disadvantages:

- Measurement marks change material's hardness

- Not suitable for too thin, too hard, plated material, curved surface

- Influenced by the operator

ROCKWELL HARDNESS TEST (HR)

Principals:

- Various types of probes with different materials and shapes

- Measuring load: < 150 kg

- Check the depth of the measuring mark

- Including: 15 regular Rockwell scales & 15 surface Rockwell scales

 

 

 

 

 

 

Applications:

For many parts with different materials, sizes and shapes

 

 

 

 

 

 

 

Advantages:

- Optical system not necessary

- Quick and easy

- Not affected by operator

- Less affected by surface roughness

Disadvantages:

Various scales with different gauges and internal loads

 

 

KNOOP HARDNESS TEST (HK)

 

Principles:

- Measuring tip is designed to measure with low loads, shallow and long measuring marks

- Measuring load: < 1 kg

Applications:

- Small, precise details

- Thin sheet material

- Coating material

 

 

 
 

Advantages:

- A method for all materials

- Can test small area and individual phase

- Coated material and measured near the edge of the specimen

- Directional properties of materials

Disadvantages:

- Can't compare between loads

- Must prepare samples carefully

VICKERS HARDNESS TEST (HV)

Principals:

- One tip / one scale for all materials

- Measuring load: 1 – 120 kg (Macro); < 1 kg (Micro)

Applications:

- Small, precise details

- Thin sheet material

- Coating material

 

 

 

 
 

Advantages:

- Comparable with multiple loads

- One method for all materials

- Able to test small area and phase individually

Disadvantages:

Requirement to prepare the sample well

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