US3314827A - Process for the hardening of metals - Google Patents
Process for the hardening of metals Download PDFInfo
- Publication number
- US3314827A US3314827A US372395A US37239564A US3314827A US 3314827 A US3314827 A US 3314827A US 372395 A US372395 A US 372395A US 37239564 A US37239564 A US 37239564A US 3314827 A US3314827 A US 3314827A
- Authority
- US
- United States
- Prior art keywords
- metal
- hardening
- titanium
- oxide
- metals
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229910052751 metal Inorganic materials 0.000 title claims description 30
- 239000002184 metal Substances 0.000 title claims description 30
- 238000000034 method Methods 0.000 title claims description 14
- 150000002739 metals Chemical class 0.000 title claims description 9
- 238000010438 heat treatment Methods 0.000 claims description 14
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 9
- 239000010936 titanium Substances 0.000 claims description 9
- 229910052719 titanium Inorganic materials 0.000 claims description 9
- 239000001301 oxygen Substances 0.000 claims description 8
- 229910052760 oxygen Inorganic materials 0.000 claims description 8
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- 229910044991 metal oxide Inorganic materials 0.000 claims description 7
- 150000004706 metal oxides Chemical class 0.000 claims description 7
- 239000000725 suspension Substances 0.000 claims description 7
- 229910052726 zirconium Inorganic materials 0.000 claims description 7
- 229910052715 tantalum Inorganic materials 0.000 claims description 6
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 claims description 6
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 3
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 239000011651 chromium Substances 0.000 claims description 3
- 238000009792 diffusion process Methods 0.000 claims description 3
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 3
- 229910052721 tungsten Inorganic materials 0.000 claims description 3
- 239000010937 tungsten Substances 0.000 claims description 3
- 229910052720 vanadium Inorganic materials 0.000 claims description 3
- 239000011248 coating agent Substances 0.000 claims description 2
- 238000000576 coating method Methods 0.000 claims description 2
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims 1
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 7
- 229910052786 argon Inorganic materials 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 3
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 239000011733 molybdenum Substances 0.000 description 2
- BPUBBGLMJRNUCC-UHFFFAOYSA-N oxygen(2-);tantalum(5+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ta+5].[Ta+5] BPUBBGLMJRNUCC-UHFFFAOYSA-N 0.000 description 2
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 229910001936 tantalum oxide Inorganic materials 0.000 description 2
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 2
- 229910001928 zirconium oxide Inorganic materials 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 229920000126 latex Polymers 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 150000002926 oxygen Chemical class 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 235000010215 titanium dioxide Nutrition 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/60—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using solids, e.g. powders, pastes
- C23C8/62—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using solids, e.g. powders, pastes only one element being applied
Definitions
- This invention relates to a process for the hardening of metals belonging to the Groups 1VB, V-B and VI-B of the expanded form of the Periodic Table of the elements by means of oxygen diffusion.
- the metals belonging to these groups are: titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten.
- the abovementioned metals are very resistant to various aggressive agents such as may occur in the chemical industry. For this reason and also because of other properties, such as a high melting point, these metals are often suitable for use as a material of construction or as a lining for reactors, pipes, valves and other parts for the chemical industry.
- these metals are often suitable for use as a material of construction or as a lining for reactors, pipes, valves and other parts for the chemical industry.
- titanium, zirconium, tantalum, and molybdennm have been used so far.
- difliculties are often encountered when in addition to corrosion resistance, demands are made on mechanical properties, such as hardness and resistance to wear.
- the hardness and the resistance to wear of titanium are relatively low and therefore it is not possible for two components which are in sliding contact, such as would occur in valves or in bearings of stirring shafts, to be made of titanium.
- Canadian Patent Number 555,952 teaches a method for hardening titanium and zirconium which uses diffusion of oxygen and nitrogen into the metal, as a result of which it becomes possible for oxygen and nitrogen to be taken up interstitially in the metal latice.
- the metal is first heated at 400-800 C. for %16 hours in air or in an oxygenand nitrogen-containing gas. This heating period is followed by heating the metal in argon at 750-1100 C. for it-8 hours. During the first heating period, oxygen and nitrogen are bound at the metal surface; during the second heating period, part of this oxygen and nitrogen diffuses into the metal and is taken up interstitially.
- the invention provides the means by which these drawback can be obviated.
- a film of metal oxide of the metal to be hardened is applied to the metal surface which is to be hardened.
- metal is subsequently heated at a temperature from 700l C. in an inert atmosphere, e.g.., argon, helium, etc., for a period from 1-60 minutes.
- an inert atmosphere e.g.., argon, helium, etc.
- the process according to the invention has the additional attraction of requiring only one heating period of short duration.
- the metal oxide before being applied is turned into a brushable suspension.
- a suspension can, for example, be prepared by combining the oxide with alcohol or with water.
- a paintlike substance is obtained, which may, for example, be applied to the surface to be hardened with a brush.
- Common layer thicknesses are those from 20 to 200 microns.
- any oxide of the metal to be hardened may be used, it is advantageous to use a metal oxide which may convert into a more stable oxide of a lower level of valency. If such an oxide is used, then at a given layer thickness, the quantity of oxygen to be supplied can be determined very exactly, resulting in even better control of the hardening process.
- Example I A test specimen of titanium was degreased and provided with a film, about 200 microns thick, of titanium oxide suspended in alcohol. Titanium white (TiO as used in the paint industry was utilized as the oxide. Subsequently, the test specimen was heated at about 900 C. in an atmosphere of argon (99.9%) for 6 minutes. After cooling down, the Vickers hardness (200 g.) was 350 kg./mm. at 30 microns below the surface and 300 kg/mm? at microns below the surface. The hardness before the hardening process was 130 kg./mm.
- Example II A test specimen of tantalum was degreased and provided with a film, about 200 microns thick, of tantalum oxide suspended in alcohol. Subsequently, the test speciment was heated at about 900 C. in an atmosphere of argon (99.9%) for six minutes.
- Example III A test specimen of zirconium was degreased and provided with a film, about 200 microns thick, of zirconium oxide suspended in alcohol. Subsequently, the test specimen was heated at about 900 C. in an atmosphere of argon (99.9% for six minutes.
- a process for hardening metal surface of metals selected from the group consisting of titanium, zirconium, vanadium, tantalum, chromium, molybdenum and tungsten, by means of oxygen ditfusion comprising: coating said metal surfaces with a brushable suspension of metal oxide corresponding to the metal surface to be hardened; and, subsequently heating the metal oxide coated metal in an inert atmopshere at a temperature from 700-1100 C. for a period from 160 minutes.
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Other Surface Treatments For Metallic Materials (AREA)
Description
3,3 14,82 7 Patented Apr. 18, .1 967 3 314 827 PROCESS FOR THE HAI KDENING F METALS Hendrik de Vries, Amsterdam, Netherlands, assignor to ShellOil Company, New York, N.Y., a corporation of Delaware No Drawing. Filed June 3, 1964, Ser. No. 372,395 Claims priority, application Netherlands, Dec. 24, 1963,
3 4 Claims. (31. 148-131) This invention relates to a process for the hardening of metals belonging to the Groups 1VB, V-B and VI-B of the expanded form of the Periodic Table of the elements by means of oxygen diffusion. The metals belonging to these groups are: titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum and tungsten.
The abovementioned metals are very resistant to various aggressive agents such as may occur in the chemical industry. For this reason and also because of other properties, such as a high melting point, these metals are often suitable for use as a material of construction or as a lining for reactors, pipes, valves and other parts for the chemical industry. Naturally since availability and price play an important part in the selection of the metal to be used, in the aforementioned applications of the metals in their pure form, mainly titanium, zirconium, tantalum, and molybdennm have been used so far. In these applicati ns, however, difliculties are often encountered when in addition to corrosion resistance, demands are made on mechanical properties, such as hardness and resistance to wear. For example, the hardness and the resistance to wear of titanium are relatively low and therefore it is not possible for two components which are in sliding contact, such as would occur in valves or in bearings of stirring shafts, to be made of titanium.
Canadian Patent Number 555,952 teaches a method for hardening titanium and zirconium which uses diffusion of oxygen and nitrogen into the metal, as a result of which it becomes possible for oxygen and nitrogen to be taken up interstitially in the metal latice. According to this method, the metal is first heated at 400-800 C. for %16 hours in air or in an oxygenand nitrogen-containing gas. This heating period is followed by heating the metal in argon at 750-1100 C. for it-8 hours. During the first heating period, oxygen and nitrogen are bound at the metal surface; during the second heating period, part of this oxygen and nitrogen diffuses into the metal and is taken up interstitially.
This method, however, has several drawbacks. The amount of gas to be bound during the first heating period cannot be easily controlled, as a result of which undesired surface compounds may be formed. Futhermore, the entire surface which is in the hot zone or heater is hardened. Owing to this, further processing, e.g., machining or bending the metal, is hampered. The hardening of parts already processed and which have to meet rigid requirements as regards dimensions is likewise undesirable in view of the deformations involved in the hardening.
The invention provides the means by which these drawback can be obviated. According to the invention, a film of metal oxide of the metal to be hardened, is applied to the metal surface which is to be hardened. The
metal is subsequently heated at a temperature from 700l C. in an inert atmosphere, e.g.., argon, helium, etc., for a period from 1-60 minutes.
only in that places. Furthermore, the process according to the invention has the additional attraction of requiring only one heating period of short duration.
Preferably the metal oxide before being applied is turned into a brushable suspension. Such a suspension can, for example, be prepared by combining the oxide with alcohol or with water. In this manner, a paintlike substance is obtained, which may, for example, be applied to the surface to be hardened with a brush. Common layer thicknesses are those from 20 to 200 microns.
It should be noted that although any oxide of the metal to be hardened may be used, it is advantageous to use a metal oxide which may convert into a more stable oxide of a lower level of valency. If such an oxide is used, then at a given layer thickness, the quantity of oxygen to be supplied can be determined very exactly, resulting in even better control of the hardening process.
Example I A test specimen of titanium was degreased and provided with a film, about 200 microns thick, of titanium oxide suspended in alcohol. Titanium white (TiO as used in the paint industry was utilized as the oxide. Subsequently, the test specimen was heated at about 900 C. in an atmosphere of argon (99.9%) for 6 minutes. After cooling down, the Vickers hardness (200 g.) was 350 kg./mm. at 30 microns below the surface and 300 kg/mm? at microns below the surface. The hardness before the hardening process was 130 kg./mm.
Example II A test specimen of tantalum was degreased and provided with a film, about 200 microns thick, of tantalum oxide suspended in alcohol. Subsequently, the test speciment was heated at about 900 C. in an atmosphere of argon (99.9%) for six minutes.
After cooling down, hardening relative to the starting material was found to have occurred.
Example III A test specimen of zirconium was degreased and provided with a film, about 200 microns thick, of zirconium oxide suspended in alcohol. Subsequently, the test specimen was heated at about 900 C. in an atmosphere of argon (99.9% for six minutes.
After cooling down hardening relative to the starting material was found to have occurred.
I claim as my invention:
1. A process for hardening metal surface of metals selected from the group consisting of titanium, zirconium, vanadium, tantalum, chromium, molybdenum and tungsten, by means of oxygen ditfusion, comprising: coating said metal surfaces with a brushable suspension of metal oxide corresponding to the metal surface to be hardened; and, subsequently heating the metal oxide coated metal in an inert atmopshere at a temperature from 700-1100 C. for a period from 160 minutes.
2. A process according to claim 1 wherein said metal is titanium, the brushable suspension is titanium oxide suspended in alcohol and the heating ternlperaure is around 900 C. and the heating time is around 6 minutes.
3. A process of claim 1, wherein said metal is zirconium, the brushable suspension is zirconium oxide suspended in alcohol and the heating temperature is around 900 C. and the heating time is around 6 minutes.
4. A process of claim 1, wherem said metal is tantalum, the brushable suspension is tantalum oxide suspended in alcohol and the heating temperature is around 900 C. and the heating time is around 6 minutes.
References Cited by the Examiner UNITED STATES PATENTS 2,163,266 6/1939 Bartels 148-6 2,681,876 6/1954 De Santis et a1. 148-133 3,111,434 11/1963 Takao et a1. 14813.1
DAVID L. RECK, Primary Examiner. R. O. DEAN, Assistant Examiner.
Claims (1)
1. A PROCESS FOR HARDENING METAL SURFACE OF METALS SELECTED FROM THE GROUP CONSISTING OF TITANIUM, ZIRCONIUM, VANADIUM, TANTALUM, CHROMIUM, MOLBDENUM AND TUNGSTEN, BY MEANS OF OXYGEN DIFFUSION, COMPRISING: COATING SAID METAL SURFACES WITH A BRUSHABLE SUSPENSION OF METAL OXIDE CORRESPONDING TO THE METAL SURFACE TO BE HARDENED; AND, SUBSEQUENTLY HEATING THE METAL OXIDE COATED METAL IN AN INERT ATMOSPHERE AT A TEMPERATURE FROM 700-1100*C. FOR A PERIOD OF FROM 1-60 MINUTES.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL302544 | 1963-12-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3314827A true US3314827A (en) | 1967-04-18 |
Family
ID=19755326
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US372395A Expired - Lifetime US3314827A (en) | 1963-12-24 | 1964-06-03 | Process for the hardening of metals |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US3314827A (en) |
| NL (1) | NL302544A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3480486A (en) * | 1965-06-18 | 1969-11-25 | Kokusai Electric Co Ltd | Heating method for local annealing or stress relieving of parts of metal articles |
| US3549427A (en) * | 1968-08-27 | 1970-12-22 | Surface Technology Corp | Wear resistant materials |
| US3549429A (en) * | 1968-08-27 | 1970-12-22 | Surface Technology Corp | Wear and abrasion resistant materials |
| US4049471A (en) * | 1976-07-26 | 1977-09-20 | Bell Telephone Laboratories, Incorporated | Technique for stabilizing contact resistance of gold plated electrical contacts |
| US5846514A (en) * | 1994-03-25 | 1998-12-08 | Isotechnika, Inc. | Enhancement of the efficacy of nifedipine by deuteration |
| US6334997B1 (en) | 1994-03-25 | 2002-01-01 | Isotechnika, Inc. | Method of using deuterated calcium channel blockers |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2163266A (en) * | 1935-12-24 | 1939-06-20 | Telefunken Gmbh | Double mosaic screen |
| US2681876A (en) * | 1949-01-24 | 1954-06-22 | Int Standard Electric Corp | Refractory coated article |
| US3111434A (en) * | 1960-08-01 | 1963-11-19 | Kobe Steel Ltd | Surface hardening of metal body consisting of or containing titanium or zirconium |
-
0
- NL NL302544D patent/NL302544A/xx unknown
-
1964
- 1964-06-03 US US372395A patent/US3314827A/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2163266A (en) * | 1935-12-24 | 1939-06-20 | Telefunken Gmbh | Double mosaic screen |
| US2681876A (en) * | 1949-01-24 | 1954-06-22 | Int Standard Electric Corp | Refractory coated article |
| US3111434A (en) * | 1960-08-01 | 1963-11-19 | Kobe Steel Ltd | Surface hardening of metal body consisting of or containing titanium or zirconium |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3480486A (en) * | 1965-06-18 | 1969-11-25 | Kokusai Electric Co Ltd | Heating method for local annealing or stress relieving of parts of metal articles |
| US3549427A (en) * | 1968-08-27 | 1970-12-22 | Surface Technology Corp | Wear resistant materials |
| US3549429A (en) * | 1968-08-27 | 1970-12-22 | Surface Technology Corp | Wear and abrasion resistant materials |
| US4049471A (en) * | 1976-07-26 | 1977-09-20 | Bell Telephone Laboratories, Incorporated | Technique for stabilizing contact resistance of gold plated electrical contacts |
| US5846514A (en) * | 1994-03-25 | 1998-12-08 | Isotechnika, Inc. | Enhancement of the efficacy of nifedipine by deuteration |
| US6334997B1 (en) | 1994-03-25 | 2002-01-01 | Isotechnika, Inc. | Method of using deuterated calcium channel blockers |
| US6818200B2 (en) | 1994-03-25 | 2004-11-16 | Isotechnika Inc. | Method of using deuterated calcium channel blockers |
| US20040253180A1 (en) * | 1994-03-25 | 2004-12-16 | Foster Robert T. | Method of making and using isotope-substituted anti-bacterial agents |
Also Published As
| Publication number | Publication date |
|---|---|
| NL302544A (en) |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US1167471A (en) | Process of modifying the ash resulting from the combustion of powdered fuel. | |
| US3314827A (en) | Process for the hardening of metals | |
| US4417929A (en) | Special brass with dezincification corrosion resistance | |
| US2788290A (en) | Method of forming a protective coating on a molybdenum-base article | |
| US3922405A (en) | Method for forming of a carbide layer of a V-a group element of the periodic table on the surface of an iron, ferrous alloy or cemented carbide article | |
| US1077977A (en) | Composite metal. | |
| US2823139A (en) | Method of increasing the scaling resistance of metallic objects | |
| US3184330A (en) | Diffusion process | |
| US2991197A (en) | Method for coating columbium and alloys thereof | |
| PL70988B1 (en) | ||
| US3800406A (en) | Tantalum clad niobium | |
| US3342628A (en) | Alloy diffusion process | |
| US3322580A (en) | Hard facing metals and alloys | |
| JP2819635B2 (en) | Stainless steel cladding materials | |
| US3202530A (en) | Method of forming a composite metal article | |
| US4379121A (en) | Brazing filler metal composition and process | |
| US3055771A (en) | Method of coating a ferrous base with aluminum | |
| US3377196A (en) | Chromium-containing diffusion coatings for metals | |
| US3236684A (en) | Alloy diffusion coating process | |
| US3362817A (en) | Bonding composition for integrally joining carbonaceous products to each other and to metals | |
| Sályi et al. | Development of Nitrided Selective Wave Soldering Tool with Enhanced Lifetime for the Automotive Industry | |
| US3249456A (en) | Diffusion coating process | |
| US3136632A (en) | Aluminum base alloy | |
| US3205090A (en) | Coating method | |
| US3196056A (en) | Methods for protecting furnace parts and the like |