Wear parts

16
Modulus of elasticity [GPa]
Grain size Impact stress
700
0,245
600
0,240
500
0,235
400
0,230
300
0,225
200
0,220
100
0,215
0
0,210
2 6 10 14 18 22 26
Co content
Modulus of elasticiy [GPa]
Poisson‘s ratio [-]
Grade characteristics
Basic guidelines for the selection of carbide grades:
Poisson‘s ratio [-]
Stress caused
by notching
Density [GPa]
15,5
15,0
14,5
14,0
13,5
13,0
Tension and
compression
(with good surface
quality!)
Resistance
to adhesion
(against metal)
Coarse/medium ++ + o o
Fine + o o +
Submicron o - + ++
Ultrafine - -- ++ ++
Within the various classes of grain sizes the following applies: the lower the Co content (=increased hardness), the higher the
wear resistance and compressive strength, but toughness decreases notably.
Modulus of elasticity, Poisson‘s ratio, density
and thermal expansion coefficient
4
2 6 10 14 18 22 26
Co content
Modulus of elasticity
Thermal expansion
Co content
[GPa] Poisson‘s ratio [-] Density [g/cm³] coefficient [10-6 1/K]
4 648 0,21 15,2 4,6
6 623 0,22 15,0 4,8
8 598 0,22 14,8 5
10 574 0,22 14,6 5,2
12 549 0,24 14,4 5,4
14 524 0,23 14,2 5,6
16 499 0,23 14,0 5,8
18 474 0,23 13,8 6
20 449 0,24 13,6 6,2
22 424 0,24 13,4 6,4
24 399 0,24 13,2 6,6
Grinding micrographs 1500 x
7
6,5
6
5,5
5
4,5
Density [GPa]
Thermal expansion coefficient [10-6 1/K]
WC-Co carbide Cermets Silicon nitride
Thermal expansion
coefficient [10-6 1/K ]