Showing papers on "Carbide published in 1981"

Light emitting diodes with high external quantum efficiency

Abstract: A light emitting diode is disclosed that emits light in the blue portion of the visible spectrum with high external quantum efficiency. The diode comprises a single crystal silicon carbide substrate having a first conductivity type, a first epitaxial layer of silicon carbide on the substrate and having the same conductivity type as the substrate, and a second epitaxial layer of silicon carbide on the first epitaxial layer and having the opposite conductivity type from the first layer. The first and second epitaxial layers forming a p-n junction, and the diode includes ohmic contacts for applying a potential difference across the p-n junction. The second epitaxial layer has side walls and a top surface that forms the top surface of the diode, and the second epitaxial layer has a thickness sufficient to increase the solid angle at which light emitted by the junction will radiate externally from the side walls, but less than the thickness at which internal absorption in said second layer would substantially reduce the light emitted from said top surface of the diode.

a‐SiC:H/a‐Si:H heterojunction solar cell having more than 7.1% conversion efficiency

Abstract: A clear valency electron controllability with substitutional impurity doping in the hydrogenated amorphous silicon carbide has been found. The amorphous silicon carbide is produced by the plasma decomposition of [SiH4(1−X)+CH4(X)] with the dopant gas of a B2H6 or PH3 system. Electrical and optical properties of doped amorphous SiC films are briefly demonstrated. Utilizing this a‐SiC:H as a wide‐band‐gap window material, we have developed a new type of a‐SiC:H/a‐Si:H heterojunction solar cell. A typical cell performance is Voc = 0.887 V, Jsc = 12.33 mA/cm2, fill factor = 0.653, and the conversion efficiency of 7.14% under AM‐1 illumination.

Compound sintered compact for use in a tool and the method for producing the same

Abstract: The invention enables to obtain a compound sintered compact for use in a cutting tool having particularly high properties in respect of bonded strength, hardness, wear resistance, plastic deformability and rigidity by bonding a diamond or cubic boron nitride containing hard layer to a cemented carbide substrate with interposition of an intermediate bonding layer. A powder for forming the intermediate bonding layer comprising cubic boron nitride in an amount less than 70 volume %, the residual part principally consisting of a compound selected from among carbides, nitrides, carbonitrides or borides of 4a, 5a, 6a transition metals of the periodic table, an admixture thereof, or a mutual solid solution compound thereof, after pressing or in the state of powder, is placed on the cemented carbide substrate to a thickness less than 2 mm, or preliminarily applied to said cemented carbide substrate, further on said powder being placed a powder for forming the hard sintered compact containing diamond or cubic boron nitride in an amount in excess of 20 volume % after pressing or in the state of powder, the whole being hot pressed under an ultrahigh pressure and a high temperature to sinter the diamond or cubic boron nitride containing hard layer and the intermediate layer as well as to bond said hard layer, intermediate layer and substrate to each other, thereby enabling to obtain a compound sintered compact having the aforesaid superior properties for use in a cutting tool.

Drill bit with carbide coated cutting face

Abstract: A drill bit for connection on a drill string has a hollow tubular body with an end cutting face provided with a tungsten carbide coated surface and an exterior peripheral stabilizer surface with cylindrical sintered carbide inserts positioned therein. Nozzle passages extend from the interior of the bit body through the cutting face for receiving a removable and interchangeable nozzle member therein. The cutting face has a plurality of recesses therein which receive, by an interference fit, a plurality of cutting elements of the type known as STRATAPAX, consisting of a cylindrical stud having an angular supporting surface with a cutting disc bonded thereon consisting of sintered carbide having a cutting surface of polycrystalline diamond. The recesses in the cutting face have milled offset recesses adjacent to the edges thereof which are sized and positioned to permit the cutting discs to be partially recessed and to restrain the cutting elements from rotation during use. The cutting face is coated with tungsten carbide to a thickness of 0.012-0.040 in. by means of a high-velocity, high-temperature plasma coating process after the cutting elements are assembled in the bit body. This process coats the steel bit body with tungsten carbide without coating or otherwise affecting the cutting inserts. The coating is metallurgically bonded to the steel bit body and protects against wear during drilling for periods of several hundred hours.

The properties and structure of the boron carbide phase

Abstract: The specimens examined were completely characterized within the homogeneity range of the carbide phase (8.8–20.0 at.% C, i.e. B10.4CB4C). An X-ray study of the lattice dimensions together with accurate measurements of the density of the compounds examined allowed us to determine the number n of atoms contained in the unit cell. The value of n varies linearly with the carbon content between B12(CBC)0.666B1.333 (“B10.4C”; n = 15.33 atoms per unit cell) and B12−xCxC¦BxC1−xC) (“B10.4C”; 0

Polycrystalline diamond and cemented carbide substrate and synthesizing process therefor

Abstract: A polycrystalline diamond body infiltrated by a silicon atom-containing metal (e.g., silicon alloy) is bonded to a substrate comprising cemented carbide with a barrier of refractory material extending between the diamonds cemented together with silicon atom-containing binder and the substrate substantially precluding migration of the cementing medium (e.g., cobalt) from the carbide substrate into contact with the silicon atom-containing bonding medium in the diamond body. The process comprises subjecting a mass of diamond powder, a quantity of silicon atom-containing metal binder material, a cemented carbide body and a barrier made of material selected from the group consisting of tantalum, vanadium, molybdenum, zirconium, tungsten and alloys thereof to the simultaneous application of elevated temperature and pressure.

Growth of Alloy Carbide Particles in Austenite

Abstract: The growth of Cr7C3, Mo6C, VC and NbC carbides in austenite was examined in the ranges of temperature from 1173 to 1473K, and time from 10 to 200h. The growth rate decreases in the order Cr7C3, Mo6C, VC and NbC. It was found that the carbides grew in two stages. The growth of carbides occurs initially by taking the solute from the matrix until an equilibrium is attained, and later by Ostwald ripening. For the carbides with lower growth rates, higher heating temperatures and/or longer times were required to reach the equilibrium. The rate equation in the stage of Ostwald ripening of alloy carbides in ternary Fe-GM alloys was derived in the case in which the lattice diffusion of M atoms controlled the growth rate. The equation well described the growth rates of the alloy carbides in the latter stage. (Received June 1, 1981)

Long-term ageing characteristics of some commercial nickel-chromium-molybdenum alloys

Abstract: The long-term ageing characteristics of some commercial Ni-Mo-Cr alloys (the high-temperature HASTELLOY alloy S and the corrosion resistant HASTELLOY alloys C-4 and C-276) at 810 K were investigated. It was found that the three alloys undergo the following long-range ordering reaction: disordered f c c lattice → ordered orthorhombic, Pt2Mo-type superlattice. Ordering was found to cause considerable strengthening without severe loss of tensile elongation. Deformation in the ordered state occurred predominantly by twinning. The corrosion rates of alloys C-4 and C-276 in boiling sulphuric-ferric sulphate solution did not seem to be greatly affected by the long-range ordering reaction. In addition to ordering, the three alloys were also found to undergo grain boundary reactions. The resulting phase in alloys S and C-4 assumed a dispersed morphology and was identified as carbide, probably of the Type M12C. In alloy C-276, however, which contains higher amounts of iron and tungsten, the boundary precipitate was in the form of a continuous layer consisting of M12C and Mu-phase. This could account for the reduced tensile elongation of alloy C-276 relative to alloys S and C-4 and also to its high corrosion rate.

Method of preparing coated cemented carbide product

Abstract: An improved process for the production of coated cemented carbide products is disclosed. A cemented carbide substrate is treated to form a metal carbide, nitride or carbonitride coating. The coated substrate is heat treated at a temperature close to or near the melting point of the binder metal of the cemented carbide to diffuse elements from the substrate into the coating. An intermediate (second) metal carbide, nitride or carbonitride coating is thereafter applied and the portion of the second is oxidized, nitrided or sulfided without detrimentally affecting the adherence of the second coating. Thereafter, a wear-resistant oxide (e.g., aluminum oxide) coating is applied to form the improved coated carbide product.

The Occurrence and Implications of Carbide-Magnetite Assemblages in Unequilibrated Ordinary Chondrites

Abstract: UNEQUILIBRATED ORDINARY CHONDRITES. G . J . T a y l o r , A. Okada, E. R. D . S c o t t , A. E. R u b i n , G. R . H u s s , a n d K. K e i l , I n s t . o f M e t e o r i t i c s and Dep t . o f G e o l o g y , Univ. o f New Mexico , A l b u q u e r q u e , NM 87131 The u n e q u i l i b r a t e d o r d i n a r y c h o n d r i t e s Semarkona , Ngawi, a n d A l l a n H i l l s A77278 c o n t a i n a s s e m b l a g e s c o n s i s t i n g p r e d o m i n a n t l y of t h e c a r b i d e s c o h e n i t e , ( F e , N i I 3 C , a n d h a x o n i t e , (Fe ,Ni )$3C6, m a g n e t i t e , k a m a c i t e , a n d t r o i l i t e , w i t h s m a l l e r amounts o f h igh-Ni t a e n i e ( u p t o 6 4 wt .% N i ) , a n d p e n t l a n d i t e . T h i s i s t h e f i r s t r e p o r t e d o c c u r r e n c e o f c a r b i d e s and m a s s i v e m a g n e t i t e i n o r d i n a r y c h o n d r i t e s . We d e s c r i b e t h e s e u n u s u a l a s s e m b l a g e s i n S e n a r k o n a a n d A77278; d a t a f o r Ngawi a r e f o r t h c o m i n g . F i n e g r a i n e d g r a p h i t e m a g n e t i t e i n c l u ~ i o n s which we o b s e r v e d i n some UOC ( 1 , 2 ) were n o t o b s e r v e d i n t h e m e t e o r i t e s d i s c u s s e d h e r e . A l t h o u g h t h e y c o n t a i n C a n d Fe 0 t h e y a r e m i n e r a l o g i c a l l y a n d 3 4' t e x t u r a l l y q u i t e d i s t i n c t f rom t h e s e a s s e m b l a g e s . Semarkona: T h i s LL3 c h o n d r i t e ( 3 ) i s one o f t h e l e a s t metamorphosed o f t h e u n e q u i l i b r a t e d o r d i n a r y c h o n d r i t e s ( 4 , 5 ) . C a r b i d e m e t a l m a g n e t i t e assemb l a g e s o c c u r a s i s o l a t e d , m i l l i m e t e r s i z e d c l a s t s be tween c h o n d r u l e s and i n some c a s e s a r o u n d c h o n d r u l e s . They seem t o have a d i s t i n c t i v e r a d i a l s t r a t i g r a p h y : c a r b i d e s a r d k a m a c i t e occupy t h e c e n t r a l r e g i o n . T h i s i s s u r r o u n d e d by a r i m o f m a g n e t i t e w h i c h i s i n t u r n s u r r o u n d e d by a l a y e r o f f i n e g r a i n e d , opaque s i l i c a t e m a t r i x ("Huss m a t r i x " r e f . 4 ) ; t h e r e i s u s u a l l y a r e a c t i o n r i m between t h e m a g n e t i t e and t h e Huss m a t r i x . A l a y e r o f m a g n e t i t e f r e q u e n t l v s u r r o u n d s t h e Huss-matr i x l a y e r . C a r b i d e s ( N i p o o r ) a r e somet imes a s s o c i a t e d w i t h t h i s o u t e r l a y e r . E x c e p t f o r m e t a l i n s i d e c h o n d r u l e s a l l t h e m e t a l i n Semarkona i s a s s o c i a t e d w i t h b o t h c a r b i d e s and m a g n e t i t e . K a m a c i t e i s c h a r a c t e r i z e d b y t h e p r e s e n c e o f 0 .2-0 .4 w t . % of Cr, P , a n d S i , e l e r r e n t s u s u a l l y n o t d e t e c t e d i n o r d i n a r y c h o n d r i t i c m e t a l ( T a b l e 1 ) . The o n l y o t h e r r t p o r t of Cr and S i i n o r d i n a r y c h o n d r i t e m e t a l i s i n c h o n d r u l e s i n B i s h u n p u r ( b ) . M e t a l s p h e r e s i n s i d e c h o n d r u l e s a r e m o s t l y p l e s s i t i c i n cornposi t i o n and c o n t a i n s i m i l a r c o n c e n t r a t i o n s of C r , P and S i a s t h e k a m a c i t e a s s o c i a t e d w i t h c a r b i d e s and m a g n e t i t e . D a u b r 6 e l i t e l a m e l l a e i n t r o i l i t e were o b s e r v e d i n one s p h e r u l e . T a e n i t e i s u n i f o r m l y h i g h i n N i a n d o c c u r s i n two l o c a t i o n s ; a s s o c i a t e d w i t h p e n t l a n d i t e a n d t r o i l i t e i t c c n t a i n s 64 w t . 7 N i a c d a s s o c i a t e d \ ~ , i t h c a r b i d e s i t c o n t a i n s 58-62 wt% N i ( T a b l e 1 ) . Minor e l e m e n t c o n c e n t r a t i o n s a r e v a r i a b l e , b u t g e n e r a l l y l o w e r t h a n i n kamaci t e . Two c a r b i d e s comor.1 y o c c u r ( T a b l e 1 ) : c c h e n i t e ( 3 5 wto/, N i ) a r d h a x o n i t e (5-6 w t . ?, N i ) . L i k e k a m a c i t e , c a h e n i t e c o n t a i n s 0 . 2 t o 0 . 4 w t % of C r , P , a n d S i ; h a x o n i t e c o n t a i n s l e s s e r amounts o f Cr a n d P (0 .1 -0 .2 wtX) a r d <0 .03 wt% S i . A t h i r d , u r i d e n t i f i e d c a r b i d e o c c u r s i n t r a c e amocn t s on t h e e d g e o f some a g g r e g a t e s ( T a b l e 1 ) . M a g n e t i t e i s n e a r l y p u r e Fe 0 b u t c o n t a i n s y.0.1 wt% of Co. P ~ n t l a n d i t e c o n t a i n s 17-18 w t 8 N i and 0 . 2 w 4 1 Co. T r o i l i t e i s p u r e PeS ( < 0 . 0 3 wt"' N i ) . A12H A77278: T h i s i s a l s o one o f t h e most u n e q u i l i b r z t e d c h o n d r i t e s ( 7 ) . C a r b i d e m a g n e t i t e a s s e m b l a g e s a r e much l e s s comnon t h a n i n Semarkona . Kamac i t e and zoned t a e n i t e a r e a b u n d a n t t h r o u g h o u t t h e m e t e o r i t e . However, m i l l i m e t e r s i z e d c l a s t s l i k e t h o s e i n Semarkona a r e p r e s e n t . The c l a s t s have h a x o n i t e a r d k a m a c i t e i n t h e c e n t r a l p a r t s , s u r r o u n d e d by m a g n e t i t e , w h i c h i s i n t u r n s u r r o u n d e d by Huss m a t r i x . U n l i k e t h e a s s e m b l a g e s i n Semarkona , a n o u t e r r i m of m a g n e t i t e i s n o t p r e s e n t and c o h e n i t e i s f o u n d o n l y a r o u n d t h e e d g e s . Kamac i t e ( T a b l e 2 ) h a s h i g h c o n t e n t s o f C r and S i , b u t l o w e r P t h a n t h o s e i n Semarkona. Both c o h e n i t e (1 .0 -2 .6 wt% N i ) a n d h a x o n i t e (4.5-5.8 wtX N i ) a r e p r e s e n t ( T a b l e 2 ) a n d a s i n Semarkona , t h e c a r b i d e s c o n t a i n s i g n i f i c a n t a n o u n t s of C r and S i . M a g n e t i t e h a s low, b u t v a r i a b l e N i c o n t e n t s (0 .1 -2 .0 wt%) a n d 0 .2-0 .4 wt% Co. P e n t l a n d i t e s have 18-21 wt% N i a n d a r e s t o i c h i o m e t r i c ( F e , N i ) S T r o i l i t e i s e s s e n t i a l l y p u r e FeS. 9 8 '

Calculation and evaluation of the gibbs energies of formation of Cr 3 C 2 , Cr 7 C 3 , and Cr 23 C 6

Abstract: A thermodynamic analysis of chemical composition data for a series of iron alloys containing chromium and carbon has been completed. These data were obtained from literature compilations for alloys equilibrated for extended times at 700 °C under neutral atmospheres. The results of this analysis, when supplemented with thermochemical data from the literature, permitted the calculation of the standard Gibbs energies of formation for the chromium carbides Cr7C3 and Cr23C6 over the range 600 to 1000 °C. These standard Gibbs energies were compared to data for these carbides from other sources. Available Gibbs energy data for the third pure chromium carbide, Cr3C2, were also evaluated. For each of these three compounds, a separation of the values for the Gibbs energy of formation into two distinct groups was observed. Each of these groups can be classed according to the nature of the experimental study used, whether it be a high temperature solid-gas equilibration involving a system of a carbide-chromic oxide-carbon (or chromium) with carbon monoxide, on one hand, or a series of investigations concerned mainly with electrolytic cell measurements, plus the work on which the present study is based. It is suggested that the differences in the Gibbs energies of formation for the respective carbides are associated with 1) the nonstoichiometric nature of these carbides and 2) possible dissolution of oxygen in the carbides during the equilibration studies.

Quantitative fractography of WC-Co cermets by Auger spectroscopy

Abstract: A general procedure has been developed to determine the area fraction occupied by the binder on the fracture surfaces of cemented carbides. The area fraction of binder on the fracture surface was obtained from the relative peak-to-peak height ratios of elements in the binder and the carbide content was measured by Auger spectroscopy on the fracture surface and an adjacent polished section and the volume fraction of binder present in the cermet. This procedure was employed to determine the area fraction of binder on the fracture surfaces of WC-Co cermets with different binder contents and carbide grain sizes. The average binder mean free path and the area fraction of binder together yield the amount of plastically deformed binder per unit area of fracture surface. The volume of deformed binder and its in situ yield strength were combined to obtain a term proportional to the amount of plastic work done per unit area of fracture surface. It is shown that the correlation between this plastic work term and the fracture toughness of the cermets is good, while correlation with binder mean free path alone is poor.

A Laser Processing Technique for Improving the Wear Resistance of Metals

Abstract: This paper describes a process whereby the surface of a wide variety of metals and alloys can be impregnated with hard, wear-resisting particles. In experiments to date, particles of TiC or WC have been injected into thin laser melted surface layers of iron, nickel, titanium, aluminum, and copper base alloys. Many other metal/particle combinations appear to be feasible, for the only fundamental limitation on the process evident to date is that the metal must not exhibit an excessive vapor pressure under the conditions of laser melting. Despite the wide range of alloy compositions experimented with, the processing conditions necessary to achieve good volume fractions of carbide are surprisingly constant. This similarity in processing conditions results in part from carrying out the carbide injection under soft vacuum conditions, thus eliminating oxidation problems without introducing problems associated with the use of shielding gases. Work in progress1 has demonstrated that several of the metal/carbide combinations produced to date exhibit good resistance to abrasive wear. It is expected that resistance to most other types of wear will also be good. Preliminary results suggest that in addition to applications involving the production of wear-resisting metal surfaces, the process may be suited to the manufacture of carbide hardened cutting tools. Furthermore, the simplicity of the process recommends it for surface alloying applications.

Structure and chemistry of a metal cluster with a four-coordinate carbide carbon atom.

Abstract: Molecular metal clusters with carbide carbon atoms of low coordination number have been prepared; they are the anionic [HFe4C(CO)12-] and [Fe4C(CO)122-] clusters. An x-ray crystallographic analysis of a tetraaminozinc salt of the latter has established a butterfly array of iron atoms with the carbide carbon atom centered above the wings of the Fe4 core. Each iron atom was bonded to three peripheral carbonyl ligands. The distances from the carbide carbon to iron were relatively short, particularly those to the apical iron atoms (1.80 A average). Protonation of the anionic carbide clusters reversibly yielded HFe4(CH)(CO)12, and methylation of the dianion gave {Fe4[CC(O)CH3](CO)12-}. Oxidation of [Fe4C(CO)122-] yielded the coordinately unsaturated Fe4C(CO)12 cluster, which was extremely reactive. Hydrogen addition to this iron cluster was rapid below 0°C, and a C—H bond was formed in this transformation.

Analysis of Electro Discharge Machining of Cemented Carbides

Abstract: Summary The difficulties of correlating Electrical Discharge Machining (EDM) process parameters with the surface integrity aspects of machined cemented carbides have been recognized. These difficulties arise not only because of complex and random nature of spark phenomenon but also due to the complex composition and structure of the cemented carbide materials. This paper analyzes the surface profiles of spark eroded cemented carbide workpieces in the light of a recently introduced Data Dependent Systems approach to EDM. The parameters of a model obtained from such an analysis are shown to render fairly accurate values of technological factors such as material removal rate, surface roughness and electrode wear. Various grades of Kennametal cemented carbides are machined with conditions recommended by the CIRP's Scientific Technical Committee E. The application of a thermal model based on the Data Dependent Systems approach to predict material removal rate in this case is demonstrated. The possibility of relating the length of cracks with the machining parameters and material properties using such a thermal model is discussed.

The conversion of chromium oxide to chromium carbide

Abstract: The thermodynamic equilibria between chromium oxide, chromium carbide, and a CO-CO2 mixture was calculated for various conditions. Experimental results on the rate of the Cr2O3 conversion to chromium carbide in CO-CO2 mixtures at 1200°C are reported. The conversion rate was low and was strongly dependent on the carbon activity.

Method of producing aluminum

Abstract: A method of producing aluminum is carried out in an electric arc furnace having primary and secondary zones separated by a divider constructed to permit the flow of molten but not gaseous products between zones. The method includes providing a charge of carbon into the primary zone containing a mixture of aluminum and aluminum carbide and providing a charge of alumina to the secondary zone, simultaneously heating the zones to react said carbon with the aluminum to form aluminum carbide in said mixture, flowing the mixture into the secondary zone, reacting the aluminum carbide in the mixture with alumina to form additional aluminum and an aluminum oxycarbide slag, flowing the slag to the primary zone for reaction with the aluminum carbide to form aluminum in the mixture, and tapping aluminum from the secondary zone.

Hard facing of metal substrates

Abstract: Method for hard-facing metal substrates is disclosed using a hard facing material consisting essentially of combined vanadium, tungsten and carbon and from about 5 to about 40% by weight of chromium carbide with up to 15% by weight in the aggregate of cobalt, iron, molybdenum and nickel.

Graphite and boron carbide composites made by hot-pressing

Abstract: Composites consisting of graphite and boron carbide were made by hot-pressing mixed powders of coke carbon and boron carbide. The change of relative density, mechanical strength and electrical resistivity of the composites and the X-ray parameters of coke carbon were investigated with increase of boron carbide content and hot-pressing temperature. From these experiments, it was found that boron carbide powder has a remarkable effect on sintering and graphitization of coke carbon powder above the hot-pressing temperature of 2000° C. At 2200° C, electrical resistivity of the composite and d(002) spacing of coke carbon once showed minimum values at about 5 to 10 wt% boron carbide and then increased. The strength of the composite increased with increase of boron carbide content. It was considered that some boron from boron carbide began to diffuse substitutionally into the graphite structure above 2000° C and densification and graphitization were promoted with the diffusion of boron. Improvements could be made to the mechanical strength, density, oxidation resistance and manufacturing methods by comparing with the properties and processes of conventional graphites.

Moessbauer spectroscopic study of passivated small particles of iron and iron carbide

Abstract: Moessbauer spectra have been recorded at room, liquid-N/sub 2/, and liquid-He temperatures for iron supported on silica after calcination, reduction, and carburization. Passivation, i.e., exposure to air, of reduced iron resulted in partial oxidation to ..beta..-FeOOH. Carburization at 300/sup 0/C in 3H/sub 2/:CO produced a mixture of chi-Fe/sub 5/C/sub 2/ and epsilon'-Fe/sub 2/ /sub 2/C in agreement with previous workers. Passivation of these carbides resulted in partial oxidation to either ..gamma..-FeOOH or an amorphous iron gel. These experiments emphasize the great potential for error if the study of these materials is confined to room-temperature spectra.

Process for recovering iron and zinc from steel- making dusts

Abstract: The object of the invention is to provide a process for the recovery of iron and zinc from steel making flue dust. The process comprises subjecting the flue dust to a carbiding step in a fluid bed in the presence of a reducing agent and a carbon supplying agent to break down the zinc ferrite structure and convert the iron to iron carbide, followed by heating the residue or product of the carbiding step to recover zinc by evaporization. The iron carbide produced may be introduced into a steel making furnace for the production of steel. An alternative procedure is the recovery of iron carbide and zinc by magnetic separation from the gangue after the carbiding step and before separation of zinc from iron carbide.

Coated product and process

Abstract: Improved adherence of oxide wear layers on hard metal or cemented carbide substrates is attained by providing a thin surface-oxidized bonding layer comprising a carbide or oxycarbide of at least one of tantalum, niobium or vanadium, optionally adding aluminum to the bonding layer, and finally providing an outer oxide wear layer.