Composite bearing structure of alternating hard and soft metal, and process for making the same
AssigneeSmith International, Inc.
InventorGunes M. Ecer
Life of this patent
Estimating the term…
Abstract
A bearing structure having a substrate and a bearing surface of alternating, spaced, hard metal and soft metal areas is disclosed. The hard metal is metallurgically bonded to the base metal substrate by rapidly melting in a predetermined pattern a powdered hardfacing composition disposed on a bearing precursor surface of the base metal substrate. The melting is accomplished by scanning with a laser beam, or like high intensity, concentrated energy source. The melt is allowed to solidify rapidly. Gaps formed between isolated areas of the solidified hard metal are filled with a melt of a soft metal. After solidification of the molten soft metal, the resulting composite structure is machined to a desired depth to provide the composite bearing surface.
Claims30
A composite metal member suitable for providing a bearing of improved wear characteristics, the member comprising:
- a substrate of a base metal composition, having a bearing precursor surface;
- a plurality of spaced areas of a hard metal composition, the spaced areas of the hard metal composition having been metallurgically bonded to the bearing precursor surface in a substantially molten state of the hard metal composition, the spaced areas protruding from the bearing precursor surface, each area of hard metal composition being substantially entirely isolated from all other areas of hard metal composition thereby forming gaps between said protruding areas, and
- a soft metal composition disposed on the bearing precursor surface to substantially fill the gaps between the protruding areas of the hard metal composition, the combined spaced areas of the hard metal composition and the soft metal composition adapted for being machined into a bearing surface.
A composite metal bearing comprising:
- a substrate member of a base metal composition including a support surface underlying a bearing surface;
- a plurality of spaced areas of a hardfacing metal different in composition than the base metal composition, said spaced areas of the hardfacing metal having been metallurgically bonded to the support surface of the substrate in a substantially molten state of the hardfacing metal, protruding from the support surface, and being isolated from one another so as to form gaps between adjacent areas, and
- a soft metal composition having a hardness of at least five Rc units less than the hardness of the hardfacing metal, the soft metal being disposed on the support surface in the gaps among the spaced areas of hardfacing metal and substantially entirely filling said gaps, the areas of the hardfacing metal and the soft metal jointly comprising the bearing surface.
A composite metal bearing have a bearing surface of alternating areas of a hardfacing metal composition and a soft metal composition, prepared by the process comprising the steps of:
- depositing a powdered hardfacing metal composition on a suitable bearing precursor surface of a metal substrate of a base metal composition;
- scanning with a high intensity energy source the powdered hardfacing composition in a predetermined pattern to cause rapid localized melting of the hardfacing composition in the predetermined pattern and to form in the predetermined pattern a metallurgical bond between the hardfacing composition and the substrate, the predetermined pattern being configured to provide spaced areas impacted by the energy source;
- permitting rapid cooling of the molten hardfacing composition whereby isolated spaced areas of solid hardfacing composition are formed which protrude from the precursor surface in the predetermined pattern;
- substantially filling all gaps between the protruding areas of the hardfacing composition with a melt of a soft metal composition;
- permitting the melt of the soft metal to solidify, and
- removing a layer of the hardfacing composition and of the soft metal composition to provide the bearing surface of the alternating areas of hardfacing metal and soft metal.
A process for preparing a composite metal bearing, comprising the steps of:
- depositing a hardfacing metal composition on a suitable bearing precursor surface of a substrate member of a base metal composition;
- scanning with a high intensity energy source the hardfacing composition in a predetermined pattern to cause rapid localized melting of the hardfacing composition in the predetermined pattern and to form in the predetermined pattern a metallurgical bond between the hardfacing composition and the substrate, the predetermined pattern being configured to provide spaced areas impacted by the energy source;
- permitting rapid cooling of the molten hardfacing composition whereby isolated, spaced areas of solid hardfacing composition are formed which protrude from the precursor surface in the predetermined pattern;
- substantially filling all gaps between the protruding areas of the hardfacing composition with a melt of a soft metal composition;
- permitting the melt of the soft metal to solidify, and
- removing a layer of the hardfacing composition and of the soft metal composition to provide a bearing surface of alternating areas of hardfacing metal and soft metal.
Dependencies are inferred from the claim text.