HARDNESS
Hardness of a material is most commonly defined as the measure of its resistance to penentration by an indenter.Hardness is also measure of strength and often has the units of stress .The indenter is often fabricated from a hard material such as diamond or hardened steel.The tips of the indenters may be conical,pyramidal,or spherical in shape.The indenter tips may also be relatively small(nano-or micro-indenters) or very large(macroindenters).Since indentation tests are relatively easy to perform(macroindentations require only limited specimen preparation),they are often used to obtain quick estimates of strength. Micro and nano-indenters have also been developed.These enable us to obtain estimates of moduli and relative estimates …show more content…
Test method D= Diameter of ball
D=impression diameter
F=load
HB=Brinell result
2. The Vickers Diamond Test
In the Vickers diamond test,the indenter used is a pyramidal shaped diamond, and as in the Brinell test
The indenter is forced into the surface of the material under the action of a static load for 10 to 15 seconds.As in the Brinell test,the Vickers Diamond hardness number,HD is given by: F= Load in kgf d = Arithmetic mean of the two diagonals, d1 and d2 in mm HV = Vickers hardness
2Fsin 136 HV= 2 HV = 1.854(F/D2), To convert HV to MPa multiply by 9.807
To convert HV to GPa multiply by
Hardness of a material is most commonly defined as the measure of its resistance to penentration by an indenter.Hardness is also measure of strength and often has the units of stress .The indenter is often fabricated from a hard material such as diamond or hardened steel.The tips of the indenters may be conical,pyramidal,or spherical in shape.The indenter tips may also be relatively small(nano-or micro-indenters) or very large(macroindenters).Since indentation tests are relatively easy to perform(macroindentations require only limited specimen preparation),they are often used to obtain quick estimates of strength. Micro and nano-indenters have also been developed.These enable us to obtain estimates of moduli and relative estimates …show more content…
Test method D= Diameter of ball
D=impression diameter
F=load
HB=Brinell result
2. The Vickers Diamond Test
In the Vickers diamond test,the indenter used is a pyramidal shaped diamond, and as in the Brinell test
The indenter is forced into the surface of the material under the action of a static load for 10 to 15 seconds.As in the Brinell test,the Vickers Diamond hardness number,HD is given by: F= Load in kgf d = Arithmetic mean of the two diagonals, d1 and d2 in mm HV = Vickers hardness
2Fsin 136 HV= 2 HV = 1.854(F/D2), To convert HV to MPa multiply by 9.807
To convert HV to GPa multiply by