Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
  • C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
  • C22C29/06—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds
  • C22C29/067—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds comprising a particular metallic binder
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
  • C22C32/0047—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
  • C22C32/0047—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents
  • C22C32/0052—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only carbides

Definitions

• titanium and titanium alloys are characterised by a particularly favourable ratio of density to strength and by a high resistance to corrosion.
• titanium and titanium alloys are used for making parts of aircraft and rockets as well as in the construction of chemical plant.
• Titanium and titanium alloys are however not very hard and their resistance to wear is poor.
• the hardness of pure titanium is less than 15 RC and conventional age-hardened titanium alloys have hardnesses between 30 and 40 RC.
• Wearing parts however are required to have hard nesses exceeding 50 RC, preferably between 60 and 70 RC, and the poor hardness of titanium and titanium alloys has therefore hitherto prevented this metal and its alloys from being used for wearing parts.
• the invention provides a sintered titanium alloy consisting essentially of from to 60% by weight of hard substance as hereinafter defined and from 40 to 90% by weight of titanium or a titanium alloy.
• the hard substance used according to the invention is hereby defined as a carbide of titanium, or a carbide of similar low density and hardness, namely chromium carbide or vanadium carbide, or a mixture of two or more of such carbides.
• the hard substance consisting of one or more of the said carbides of titanium, chromium and vanadium increases the wear resistance and hardness without adversely aifecting the low density and corrosion resistance of the sintered titanium or titanium alloy.
• EXAMPLE 1 The hardness of sintered pure titanium of about 15 RC can be raised to between 65 and 70 RC by forming a mixture of titanium and 30% by weight of titanium carbide having a content of free carbon below 0.03%, and sintering the said mixture to obtain a sintered alloy of density 4.57 g./cc.
• EXAMPLE 2 An age-hardened titanium alloy consisting essentially of 6.0% aluminium 4.0% vanadium, balance titanium, had a maximum hardness when sintered of 45 RC and a density of 4.43 g./cc.
• the density of the sintered alloy was slightly increased to 4.50 g./cc., and the hardness was substantially increased to between 60 and 62 RC.
• EXAMPLE 3 A titanium alloy consisting essentially of 7.0% aluminium, 4.0% molybdenum, balance titanium when sintered had a maximum hardness of 35 to 40 RC and a density of 4.88 g./cc.
• EXAMPLE 4 A titanium alloy consisting essentially of 5.0% aluminium, 2.5% tin, balance titanium when sintered had a hardness of 25 to 30 RC and a density of 4.46 g./cc.
• the hardness of the sintered alloy was between 57 and 60 RC, the density being 4.47 g./cc.
• the hard sintered titanium alloys according to the invention may be used for making parts that are required to have a high resistance to corrosion, particularly to oxidation attack and to media containing chlorine ions as well as being wear resistant and hard.
• Examples of uses to which the wear-resistant and hard sintered titanium alloys according to the invention may be applied include atomisers, nozzles, stufling boxes, sealing rings, mixer, blades, drain agefittings, stirrers, valves and holders for the chemical, metal, electroplating, paper making, ore dressing, electric, photographic, aircraft and aerospace industries.
• the sintering process which may be used for the titanium alloys according to the invention includes grinding a dry mixture of titanium or titanium alloy powder and the pulverulent hard substances as hereinbefore defined in a substantially noninfiammable and non-oxidising liquid to a grain size of less than 5 pm. If the matrix is a titanium alloy the powdered alloy or either of the basic components of the titanium alloy or key alloy may be mixed in powder form and ground with pulverulent hard substance. When alloy components are used, alloy formation between the titanium and the alloying elements takes place during the subsequent sintering operation to form the titanium alloy matrix.
• the ground mixture is vacuum dried for the removal of grinding liquid, precautions being taken to avoid selfignition of the finely ground titanium powder, preferably in the mixture, such residuum liquid also provides protection against oxidation and serves as a compacting aid.
• the dried mixture is compacted, and the compacted pressing thus obtained are sintered in a vacuum or under a protective gas, preferably in a vacuum higher than 10 torr, at a temperature between 1500 and 1600 C., depending on the particular alloy used.
• a sintered titanium alloy of high wear resistance and of a hardness exceeding 50 RC consisting essentially of:
• a sintered titanium alloy of high Wear resistance and of a hardness exceeding 50 RC consisting essentially of:

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Powder Metallurgy (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=5783057

Family Applications (1)

Country Status (5)

Cited By (7)

Families Citing this family (2)

• 1971
  • 1971-08-24 GB GB3964971A patent/GB1301629A/en not_active Expired
  • 1971-08-27 US US00175717A patent/US3737290A/en not_active Expired - Lifetime
  • 1971-09-15 NL NL7112682A patent/NL7112682A/xx unknown
  • 1971-09-16 BE BE772676A patent/BE772676A/xx unknown
  • 1971-09-16 FR FR7133348A patent/FR2107738A5/fr not_active Expired

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