Hard metal cemented carbide
A cemented carbide suitable as a high performance hard metal material for wire drawing of high-tensile strength alloys is provided. The cemented carbide may include a relatively low binder content with additives Cr, Ta and/or Nb to provide high wear and corrosion resistance, high thermal conductivity, high hardness and a desired hardness to fracture toughness correlation.
1. A cemented carbide, comprising:
at least 95 wt. % WC;
Co present in an amount from 3 to 4 wt. %;
Cr present in an amount from 0.10 to 0.50 wt. % and a wt. %-quotient of Cr/Co is in a range from 0.06 to 0.07;
Ta present in an amount from 0.05 to 0.30 wt. %;
Nb present in an amount from 0.01 to 0.07 wt. %; and
V present in an amount from 0.05 to 0.20 wt. %,
wherein an impurity including any one of Fe, Ru, or Y is present in the cemented carbide, and
wherein the cemented carbide has a Vickers hardness HV30 from 1950 to 2150 measured by using 30 kgf (HV30) and a Palmqvist fracture toughness (K Ic ) from 8.0 to 9.5 MPa √m calculated according to
K
1
c
=
A
H
V
P
∑
L
,
where A is a constant of 0.0028, HV is hardness (N/mm 2 ), P is applied load (N), and ΣL is sum of crack lengths (mm) of imprints.
2. The cemented carbide according to claim 1 , wherein the Nb is present in an amount from 0.02 to 0.06 wt. %.
3. The cemented carbide according to claim 1 , wherein the WC has a grain size in a range from 0.2 to 0.8 μm.
4. The cemented carbide according to claim 3 , wherein the grain size is in the range from 0.2 to 0.6 μm.
5. The cemented carbide according to claim 1 , comprising a density in a range from 14.5 to 15.5 g/cm 3 .
6. A metal wire drawing die, comprising the cemented carbide according to claim 1 .
7. A cemented carbide, comprising:
at least 95 wt. % WC;
Co present in an amount from 3 to 4 wt. %;
Cr present in an amount from 0.10 to 0.50 wt. % and a wt. %-quotient of Cr/Co is in a range from 0.06 to 0.07;
Ta present in an amount from 0.05 to 0.30 wt. %;
Nb present in an amount from 0.01 to 0.07 wt. %; and
V present in an amount from 0.05 to 0.20 wt. %,
wherein an impurity including any one of Fe, Ru, or Y is present in the cemented carbide, and
wherein the cemented carbide is an etched cemented carbide with a Murakami etchant to measure a grain size of the WC, which is in a range from 0.2 to 0.8 μm.
8. A cemented carbide, consisting of:
at least 95 wt. % WC;
Co present in an amount from 3 to 4 wt. %;
Cr present in an amount from 0.10 to 0.50 wt. % and a wt. %-quotient of Cr/Co is in a range from 0.06 to 0.07;
Ta present in an amount from 0.05 to 0.30 wt. %;
Nb present in an amount from 0.01 to 0.07 wt. %; and
V present in an amount from 0.05 to 0.20 wt. %,
wherein an impurity including any one of Fe, Ru, or Y is present in the cemented carbide, and
wherein the cemented carbide has a Vickers hardness HV30 from 1950 to 2150 measured by using 30 kgf (HV30) and a Palmqvist fracture toughness (K Ic ) from 8.0 to 9.5 MPa √m calculated according to
K
1
c
=
A
H
V
P
∑
L
,
where A is a constant of 0.0028, HV is hardness (N/mm 2 ), P is applied load (N), and ΣL is sum of crack lengths (mm) of imprints.