Nickel-Based Alloy

Abstract

Nickel-based alloy, consisting of (in % by mass) Al 1.2-<2.0% Si 1.2-<1.8% C 0.001-0.1% S 0.001-0.1% Cr 0.03-0.1% Mn 0.03-0.1% Cu max. 0.1% Fe 0.02-0.2% Mg 0.005-0.06% Pb max. 0.005% Y 0.05-0.15% and Hf 0.05-0.10% or Y 0.05-0.15% and La 0.05-0.10% or Y 0.05-0.15% and Hf 0.05-0.10% and La 0.05-0.10% Ni remainder together with manufacturing-related impurities.

Description

BACKGROUND OF THE INVENTION

The invention relates to a nickel-based alloy having silicon, aluminum, and reactive elements as alloy components.

Nickel-based alloys are used inter alia for producing electrodes for ignition elements in internal combustion engines. Two damaging mechanisms affect the wear of such electrodes, specifically high temperature corrosion and spark erosion.

Wear from high temperature corrosion can be determined by measuring losses in weight and using metallographic examinations after exposure to pre-specified testing temperatures.

Spark erosion is combustion of material that is caused by ignition sparks. With each flashover, a limited volume of electrode material is melted and in part evaporated.

The type of oxide layer formation is particularly significant for both damaging mechanisms.

Different alloy elements for nickel-based alloys are known for attaining optimum oxide layer formation for the specific application. Thus, for instance, aluminum has a positive effect on oxide layer formation. It is also known that reactive elements can improve the adhesion of the oxide layer that forms and can increase life cycle.

Known from GB-A 2031950 is a nickel alloy comprising (in % by weight) about 0.2 to 3% Si, about 0.5% or less Mn, at least two metals selected from the group comprising about 0.2 to 3% Cr, about 0.2 to 3% Al, and about 0.01 to 1% Y, and the remainder nickel.

DE-A 102 24 891 suggests an alloy that is based on nickel and that has (in % by weight) 1.8 to 2.2% silicon, 0.05 to 0.1% yttrium and/or hafnium and/or zirconium, 2 to 2.4% aluminum, and the remainder nickel. It is very difficult to process such alloys given the high aluminum and silicon content and they are thus not well suited for use on an industrial scale.

SUMMARY OF THE INVENTION

The object of the inventive subject-matter is to provide a nickel-based alloy that can be used to increase the life cycle of components produced therefrom by increasing resistance to spark erosion and oxidation while simultaneously providing good formability and weldability.

This object is attained using a nickel-based alloy that contains (in % by weight):

• • Al 1.2-<2.0%
  • Si 1.2-<1.8
  • C 0.001-0.1%
  • S 0.001-0.1%
  • Cr 0.03-0.1%
  • Mn 0.03-0.1%
  • Cu max. 0.1%
  • Fe 0.02-0.2%
  • Mg 0.005-0.06%
  • Pb max. 0.005%
  • Y 0.05-0.15% and Hf 0.05-0.10% or
  • Y 0.05-0.15% and La 0.05-0.10% or
  • Y 0.05-0.15% and Hf 0.05-0.10% and La 0.05-0.10%
  • Ni remainder and production-related impurities

Preferred alternative embodiments of the inventive subject-matter are as follows.

Nickel-based alloy having (in % by weight):

• • Al 1.2-<2.0%
  • Si 1.2-<1.8
  • C 0.001-0.05%
  • S 0.001-0.05%
  • Cr 0.03-0.1%
  • Mn 0.03-0.1%
  • Cu max. 0.1%
  • Fe 0.02-0.2%
  • Mg 0.005-0.06%
  • Pb max. 0.005%
  • Y 0.10-0.15% and Hf 0.05-0.10%
  • Ni remainder and production-related impurities

Nickel-based alloy having (in % by weight):

• • Al 1.2-<2.0%
  • Si 1.2-<1.8
  • C 0.001-0.05%
  • S 0.001-0.05%
  • Cr 0.03-0.1%
  • Mn 0.03-0.1%
  • Cu max. 0.1%
  • Fe 0.02-0.2%
  • Mg 0.005-0.06%
  • Pb max. 0.005%
  • Y 0.10-0.15% and La 0.05 to 0.10%
  • Ni remainder and production-related impurities

Nickel-based alloy having (in % by weight):

• • Al 1.2-<2.0%
  • Si 1.2-<1.8
  • C 0.001-0.05%
  • S 0.001-0.05%
  • Cr 0.03-0.1%
  • Mn 0.03-0.1%
  • Cu max. 0.1%
  • Fe 0.02-0.2%
  • Mg 0.005-0.06%
  • Pb max. 0.005%
  • Y 0.10-0.15% and Hf 0.05-0.10% and La 0.05-0.10%

Thus, there are three conceivable variants in terms of the reactive elements, specifically:

• • Y+Hf
  • Y+La and
  • Y+Hf+La

The inventive nickel-based alloy can preferably be used as a material for electrodes for spark plugs in gasoline engines.

Selectively adjusting the elements Al, Si, Cr, Mn, and Mg, as well as the reactive elements Y, Hf, La in their respective combinations can bring about an increased life cycle for electrode materials by increasing the spark erosion resistance and oxidation resistance while simultaneously promoting formability and weldability.

The element Mg is particularly important in terms of binding sulfur so that in this case it is possible to selectively adjust low sulfur content in the inventive nickel-based alloy.

Preferred aluminum content (in % by weight) ranges from 1.2-1.5%.

Preferred silicon content (in % by weight) ranges from between 1.2 and 1.8%, in particular 1.2 and 1.5%, while the preferred Mg content (in % by weight) is adjusted between 0.008 and 0.05%.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are plots of the results of laboratory tests.

DETAILED DESCRIPTION OF THE INVENTION

The table compares five inventive laboratory batches to two industrial batches belonging to the prior art.

Laboratory batch 1132 is an example in which the reactive elements Y+Hf are provided in the inventive nickel-based alloy.

Laboratory batch 1140 is an example in which the reactive elements Y+La are present in the inventive alloy.

Laboratory batches 1141 and 1142 disclose examples in which Y+La+Hf were adjusted as reactive elements in the inventive nickel-based alloy.

Ele-	LB	LB	LB	LB
ment	1132	1140	1141	1142	NiCr2MnSi	NiAl1Si1Y
Ni	96.83	96.91	96.89	96.79	96.24	97.56
Si	1.47	1.36	1.36	1.42	0.49	0.96
Al	1.38	1.43	1.44	1.40	0.02	0.98
Zr
Y	0.15	0.12	0.14	0.13		0.17
Hf	0.08		0.078	0.073
La		0.09	0.096	0.096
Ti				0.1	0.01	0.01
C	0.002	0.006	0.004	0.003	0.003	0.03
S	0.002	0.002	0.002	0.002	0.002	0.002
Co					0.04	0.05
Cu					0.01	0.01
Cr	0.04	0.03	0.06	0.04	1.57	0.01
Zr					0.01
Mg	0.02	0.03	0.01	0.03	0.02	0.04
Mn	0.06	0.03	0.03	0.06	1.48	0.02
Fe	0.03	0.03	0.03	0.04	0.08	0.13
Pb					0.001	0.001

FIGS. 1 and 2 depict weight loss examinations for the alloys in accordance with the table at temperatures of 900° C. and 1000° C.

At just 900° C. the two comparison alloys exhibit flaking of the previously constructed oxide layer. Although this also occurs with the inventive alloys at 1000° C., it does not occur to the same extent as in the comparison alloys.

Claims

1. Nickel-based alloy comprising, in % by weight: Al 1.2-<2.0%Si 1.2-<1.8C 0.001-0.1%S 0.001-0.1%Cr 0.03-0.1%Mn 0.03-0.1%Cu max. 0.1%Fe 0.02-0.2%Mg 0.005-0.06%Pb max. 0.005%Y 0.05-0.15% and Hf 0.05-0.10% orY 0.05-0.15% and La 0.05-0.10% orY 0.05-0.15% and Hf 0.05-0.10% and La 0.05-0.10%Ni remainder and production-related impurities

2. Nickel-based alloy in accordance with claim 1, comprising, in % by weight: Al 1.2-<2.0%Si 1.2-<1.8C 0.001-0.05%S 0.001-0.05%Cr 0.03-0.1%Mn 0.03-0.1%Cu max. 0.1%Fe 0.02-0.2%Mg 0.005-0.06%Pb max. 0.005%Y 0.10-0.15% and Hf 0.05-0.10%Ni remainder and production-related impurities

3. Nickel-based alloy in accordance with claim 1, comprising, in % by weight: Al 1.2-<2.0%Si 1.2-<1.8C 0.001-0.05%S 0.001-0.05%Cr 0.03-0.1%Mn 0.03-0.1%Cu max. 0.1%Fe 0.02-0.2%Mg 0.005-0.06%Pb max. 0.005%Y 0.10-0.15% and La 0.05to 0.10%Ni remainder and production-related impurities

4. Nickel-based alloy in accordance with claim 1, further comprising, in % by weight: Al 1.2-<2.0%Si 1.2-<1.8C 0.001-0.05%S 0.001-0.05%Cr 0.03-0.1%Mn 0.03-0.1%Cu max. 0.1%Fe 0.02-0.2%Mg 0.005-0.06%Pb max. 0.005%Y 0.10-0.15% and Hf 0.05-0.10% and La 0.05-0.10%Ni remainder and production-related impurities

5. Nickel-based alloy in accordance with any of claims 1 through 4, further comprising, in % by weight: Al 1.2-1.5%Si 1.2-1.5%

6. Nickel-based alloy in accordance with any of claims 1 through 4, further comprising, in % by weight: Mg 0.008-0.05%

7. Nickel-based alloy in accordance with any of claims 1 through 4, further comprising, in % by weight: Y+Hf 0.11-0.18%

8. Nickel-based alloy in accordance with any of claims 1 through 4, further comprising, in % by weight: Y+La 0.11-0.18%

9. Nickel-based alloy in accordance with any of claims 1 through 4, further comprising, in % by weight: Y+Hf+La 0.18-0.22%

10. Nickel-based alloy in accordance with any of claims 1 through, further comprising, in % by weight: Y+Mg 0.11-0.13%

11. A spark plug electrode comprising the nickel-based alloy in accordance with any of claims 1 through 4.