Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
  • F02F1/00—Cylinders; Cylinder heads 
  • F02F1/18—Other cylinders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
  • B22F1/12—Metallic powder containing non-metallic particles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/20—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by extruding
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/04—Making non-ferrous alloys by powder metallurgy
  • C22C1/0408—Light metal alloys
  • C22C1/0416—Aluminium-based alloys
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
  • F02F7/00—Casings, e.g. crankcases
  • F02F7/0085—Materials for constructing engines or their parts
  • F02F2007/009—Hypereutectic aluminum, e.g. aluminum alloys with high SI content
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
  • F05C2201/00—Metals
  • F05C2201/02—Light metals
  • F05C2201/021—Aluminium

Definitions

• the present invention relates to jackets of internal combustion or internal combustion engines, the structure of which has grains of silicon calibrated and dispersed in a matrix of an eutectic aluminum-silicon alloy. It also relates to some of the methods of obtaining these shirts.
• Engine liners made from aluminum are not new, but their use has always posed problems of compatibility of their working surface with engine elements such as the pistons which are in contact with them.
• the present invention therefore relates to an internal combustion engine liner based on an aluminum-eutectic silicon alloy possibly containing other elements and characterized in that its structure has a distribution of calibrated silicon grains of dimensions between 20 and 50 ⁇ m.
• this jacket is that made up of an aluminum-silicon eutectic alloy matrix, that is to say containing about 12% of silicon and in which no primary silicon grain appears.
• This alloy may optionally contain other addition elements which contribute to improving its mechanical characteristics or certain properties in relation to the friction or wear behavior.
• calibrated silicon grains that is to say corresponding to a grading curve as narrow as possible and whose dimensions are in any case between 20 and 50 m. This excludes all fine silicon particles as well as grains of too large size which contribute to reducing the desired compatibility.
• silicon grains have a purity greater than 99.5% and preferably a calcium content of less than 300 pp. They can optionally be treated to remove iron. Their facies are different depending on the method of production. Thus, one can have not only conventional grains prepared by grinding and sieving, but also grains produced by spraying liquid silicon which have a more rounded outline.
• the aluminum-silicon alloy matrix use is preferably made of eutectic alloys of the A-S12U4G type, that is to say containing elements such as copper and magnesium having for effect of improving mechanical strength.
• the friction properties of the shirts are favored by the presence of additives such as graphite or any other body playing an equivalent role.
• an artificial graphite of the granular type is used, a shape which integrates physically well with the other components of the jacket. The most suitable proportion is between 3 and 10% by weight of the mass within which it is dispersed.
• the Applicant has also found that it is possible to further improve the performance of the sleeve-piston assemblies from the compatibility point of view and to remedy in particular the appearance of certain point bonding phenomena which appear when the sleeve works above the limit temperatures generally. allowed, by adding in the jacket a dispersion of at least one intermetallic compound, distinct from that of such compounds likely to exist within the alloy and whose melting point is higher than 700 ° C.
• the invention also consists in having in the jacket in addition to the calibrated silicon grains, a dispersion of at least one intermetallic compound.
• this dispersion is different from the structure and / or composition point of view from that which might be present in the base alloy. Indeed, it is possible that this alloy contains certain elements capable of forming between them intermetallic compounds during its preparation by powder metallurgy. However, these compounds belong to the very structure of the base alloy and therefore have nothing to do with that (or those) concerned by the invention. These i ⁇ ter- metallic compounds constituting this dispersion are chosen from those which have a melting temperature higher than 700 ° C.
• the intermetallic compound Ni, Sn in which three nickel atoms are combined with a tin atom to form these crystals of the ..hexagonal type, has proved to be particularly effective both in its functions of "non-bonding agent" "and in those of lubricating and wear-resistant product.
• Such compounds must be distributed regularly in the mass of the jacket in the form of grains.
• these grains are preferably calibrated, that is to say that they respond to a particle size curve as narrow as possible and whose dimensions are in any case between 5 and 50 ⁇ m. This excludes, on the one hand, grains which are too fine and which, due to their high specific surface area, lead to seizing of the tools for making shirts, on the other hand, grains which are too large and which cause the coefficient of friction to increase.
• the grains of metallic compound can have a different facies depending on their mode of delivery. Thus it is possible not only to have grains prepared by grinding but also grains produced by spraying the compound in the liquid state which therefore have a more rounded outline.
• the base alloy constituting the matrix of the material of the invention in addition to the alloy of the type AS ′′ U, G, it is also possible to use an alloy of the type AS ′′ Z ,. G ⁇ .
• the invention also relates to some of the methods for obtaining such shirts. These methods have a common phase of dividing the aluminum-silicon eutectic alloy from the liquid state into a powder. This is obtained by all existing processes such as, for example, centrifugal spraying, atomization, etc. This powder is then sieved to remove particles of dimensions not between 60 and 400 ⁇ m and then mixed with silicon grains of particle size between 20 and 50 ⁇ m and in a quantity such that they represent 5 to 15 S. by weight of the mass of the jacket j optionally 3 to 10% by weight of graphite or any other element capable of improving the quality of the jacket such as silicon carbide to increase its hardness or tin to make it more suitable for friction.
• an intermetallic compound is incorporated in the form of grains according to the percentages by weight of between 5 and 15% and of dimensions between 5 and 50 ⁇ m. After homogeni-. sation suitable, such a mixture can then be treated with two different vials, either by sintering or by spinning.
• the powder mixture is shaped by cold compression in a vertical or isostatic press, then sintered under a controlled atmosphere.
• the shirt thus obtained is then machined to suitable dimensions.
• the mixture is cold compressed in the form of a billet or loaded directly into the pot of a press and then, spun in the form of a tube after possible preheating away from the atmosphere.
• the spinning equipment used is well known to those skilled in the art. It can be either a bridge tool or a floating needle-plate assembly. The tube thus obtained at the outlet
• IA of the press is erected, cut to the length of the shirts and the latter are then machined.
• the mixture can also be compressed in the form of pawns which are subjected to reverse spinning so as to form buckets, the bottom and the opposite edge of which are then cut off to collect liners which are then machined. It is also possible to directly quench the cups after spinning.
• the invention can be illustrated by means of three figures appended to the present application and which represent drawings of micrographs drawn under a magnification of 200, of engine liners manufactured according to different techniques.
• FIG. 1 corresponds to a jacket obtained by casting a hypereutectic aluminum-silicon alloy
• Figure 2 to a jacket obtained by spinning hypereutectic aluminum alloy silicon powder
• FIG. 3 to a jacket according to the invention obtained by spinning a mixture of powder of aluminum alloy-eutectic silicon and of calibrated silicon powder.
• the aluminum-silicon alloy is an A-S17U4G according to the standards of the Aluminum Association which therefore contains 17% of silicon and therefore is said to be hypereutectic in silicon.
• the aluminum-silicon alloy is also an A-S17U4G but resulting from the spinning of powder obtained by atomization.
• the primary silicon grains (3) Due to the high cooling speed used to form this powder, the primary silicon grains (3) have a relatively small size comparable to that of eutectic silicon, and in any case less than that resulting from conventional casting. Also shown in this figure are graphite particles (4) which lengthen in the spinning direction and represent approximately 3% by weight of the liner mass.
• the excessive fineness of the silicon grains, of the jackets thus formed is the cause of their deterioration during tests under particularly severe conditions.
• the aluminum-silicon alloy is an A-S12U4G which contains 12% of silicon and therefore is said to be eutectic in silicon. It also results from the spinning of powder obtained by atomization, but was added according to the invention before spinning, about 5% by weight of silicon powder whose grains (5) have a facies of particles resulting from grinding and a dimension between 20 and 50 ⁇ m. These grains are dispersed in a eutectic matrix within which a distinction is made between silicon particles (7) which have coaleas and graphite particles (6) associated at a rate of 35% by weight. Note the completely original texture of the shirts according to the invention, a texture which contributes to significantly improving the compatibility with the pistons of the shirts thus produced.
• the shirts forming the subject of the invention find their application in particular in the automobile industry and in any kind of industry where it is sought to have assemblies, piston-plunger of good compatability from alloys of 'aluminum.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Combustion & Propulsion (AREA)
• General Engineering & Computer Science (AREA)
• Powder Metallurgy (AREA)
• Manufacture Of Metal Powder And Suspensions Thereof (AREA)
• Cylinder Crankcases Of Internal Combustion Engines (AREA)
• Manufacture Of Alloys Or Alloy Compounds (AREA)

Priority Applications (2)

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Publications (1)

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Family Applications (1)

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Cited By (1)

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Citations (9)

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• 1982
  • 1982-12-09 FR FR8220982A patent/FR2537654B2/fr not_active Expired
• 1983
  • 1983-06-15 WO PCT/FR1983/000120 patent/WO1984000050A1/fr active IP Right Grant
  • 1983-06-15 EP EP83901824A patent/EP0112848B1/fr not_active Expired
  • 1983-06-15 DE DE8383901824T patent/DE3363726D1/de not_active Expired
  • 1983-06-15 US US06/589,064 patent/US4650644A/en not_active Expired - Fee Related
  • 1983-06-15 JP JP58501912A patent/JPS59500779A/ja active Granted
  • 1983-06-15 IT IT21630/83A patent/IT1194273B/it active
  • 1983-06-16 ES ES523319A patent/ES523319A0/es active Granted
  • 1983-06-16 CA CA000430576A patent/CA1237919A/fr not_active Expired

Patent Citations (9)

Non-Patent Citations (1)

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