Properties and testing methods of metals Flashcards
The 3 hardness tests are
Brinell, Vickers, Rockwell
What indenter does Vickers hardness test use?
square-based pyramid with 136degree apex angle
Advantages of Vickers Hardness test
Produces negligible surface damage from small impression made
Suitable for testing on thin sheets
Disadvantages of Vickers Hardness test
More surface preparation work (to obtain better surface finish)
Indenter is expensive
Rockwell minor load is used for
taking up slackness in system
eliminate errors that is caused by uneven surface
What is the minor load for Rockwell testing?
10 kgf
Advantages of Rockwell Hardness test
Fast results and gives direct hardness number
Used on both hard and soft materials
Disadvantage of Rockwell hardness test
Different loads and indentors must be used for different scales
Cannot be used on thin sheets and foils
What are the major load for Rockwell A B C?
A: 60 kgf
B: 100 kgf
C: 150 kgf
Types of indentor for Rockwell A B C
A: Brale or diamond cone
B: 1/16 inch (1.6mm) hardened steel ball
C: 120degree apex angle diamond cone or brale
Applications for Rockwell B
Copper and Aluminium alloys
Applications for Rockwell C
Hardened steel
Hard cast iron
Applications for Rockwell A
Cemented carbide
Thin steel
Energy level absorbed by impact test from brittle and ductile metals
Brittle metals: less energy to break
Ductile metals: more energy to fracture
Types of impact tests
Charpy, Izod and Hounsfield
