EP0275426B1 - Procédé et installation pour la fabrication de pièces métalliques renforcées par des fibres - Google Patents

Procédé et installation pour la fabrication de pièces métalliques renforcées par des fibres Download PDF

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Publication number
EP0275426B1
EP0275426B1 EP87117752A EP87117752A EP0275426B1 EP 0275426 B1 EP0275426 B1 EP 0275426B1 EP 87117752 A EP87117752 A EP 87117752A EP 87117752 A EP87117752 A EP 87117752A EP 0275426 B1 EP0275426 B1 EP 0275426B1
Authority
EP
European Patent Office
Prior art keywords
casting
vacuum
mould cavity
filling chamber
fibre
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
Application number
EP87117752A
Other languages
German (de)
English (en)
Other versions
EP0275426A2 (fr
EP0275426A3 (en
Inventor
Herbert Dr. Woithe
Josef Dipl.-Ing. Penkava
Gerhard Prof. Dr.-Ing. Habil. Phys. Ibe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Vereinigte Aluminium Werke AG
Original Assignee
Vereinigte Aluminium Werke AG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Vereinigte Aluminium Werke AG filed Critical Vereinigte Aluminium Werke AG
Priority to AT87117752T priority Critical patent/ATE68732T1/de
Publication of EP0275426A2 publication Critical patent/EP0275426A2/fr
Publication of EP0275426A3 publication Critical patent/EP0275426A3/de
Application granted granted Critical
Publication of EP0275426B1 publication Critical patent/EP0275426B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • B22D17/14—Machines with evacuated die cavity
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D19/00—Casting in, on, or around objects which form part of the product
    • B22D19/14—Casting in, on, or around objects which form part of the product the objects being filamentary or particulate in form

Definitions

  • the invention relates to a fiber-reinforced die-cast part and to a method and a device for its production by vacuum die-casting technology, the metering of the metal being carried out by means of a vacuum via a riser pipe and a suction opening into the filling chamber, and the metal being pressed into the mold cavity by means of an ancillary run of the casting piston .
  • Vacuum die casting technology for horizontal and vertical cold chamber die casting machines is known.
  • the melt is drawn into the filling chamber via a riser pipe by means of a vacuum, which is arranged above the mold cavity in the direction of flow of the molten metal.
  • an apparatus for the production of composite materials which consists of a first receiving chamber for the molten metal and a second receiving chamber for a reinforcing material in the form of a porous, low-density body.
  • air can be drawn off through a line provided in the pressure stamp in order to establish the pressure equilibrium between the upper and lower side of the porous body. Since the vacuum suction process begins at the lower section by 0.1 to 1 second earlier than the vacuum process in the upper section, the molten metal on the stamp part can solidify to a relatively thick layer and thus prevent air suction from below. In this way, the hot molten metal is prevented from abruptly rising and forming bubbles when the size of the negative pressure at the lower portion is slightly smaller than the size of the negative pressure at the upper portion.
  • the object of the present invention is to develop a fiber-reinforced die-cast part and a method and a device for its production, in which the inclusion of gases is avoided and the wetting of the fibers by the inflowing melt is improved. According to the invention, this is done by the features specified in the claims.
  • the arrangement of the vacuum connection between the filling chamber and the mold space in the region of the casting run has the advantage that the vapors of the piston lubricant heated by the liquid metal which is filled or sucked into the filling chamber of the die casting machine are sucked out separately and directly from the filling chamber.
  • the application of the present method is particularly important with regard to volatile alloy components, e.g. Magnesium and its oxides, which are easily formed when the melt overheats and are deposited in the mold cavity.
  • volatile alloy components e.g. Magnesium and its oxides
  • With the present method it is possible to keep the die cavity of the die casting machine free of air and other residual gases and in particular the inner surface of the fiber arrangements used free of any contamination by condensed residues while at the same time maintaining the automatic suction of the molten metal for the shot.
  • the mold cavity 7 which has the suction channel 9 with filter 10, vacuum control valve 11 and the vacuum container 12 and vacuum pump 13 in the region of the casting run 8.
  • Figure 2 shows the filling chamber 1 in cross section with a subsequent pouring run 8, in which the vacuum channel 9 opens.
  • the mold cavity 7a, b is connected to an annular suction 14a, b, c, which provides additional degassing of the fiber molded body before the melt penetrates.
  • FIG. 3 schematically shows a mold cavity 15 which is formed by two mold halves 16a, 16b. At the outer ends of the mold halves 16a, b 2 bores 17a, 17b and 18a, 18b are provided for receiving magnetic bodies 19-22.
  • a cylindrical fiber molded body 23 is inserted into the mold cavity 15. This has annular spacers 24, 25 made of ferromagnetic material at the respective end points. It is possible to use the magnetic bodies 19-22 both from normal magnets and in the form of electromagnets.
  • a molded fiber body or a fiber insert is produced from long and / or short fibers by known methods.
  • Al2O3 and the SiC fibers are preferred as fiber material, but other high-strength metal fibers and carbon fibers as well as boron fibers can also be processed.
  • the preferred Al2O3-containing fibers are non-magnetic and are preformed into a firm bond using the known sintering technique.
  • Known silicate-based binders e.g. "LUDOX" from DuPont can be used.
  • the fiber molding is inserted into the mold cavity 7, which is located in the movable and / or fixed mold half 6a, b or 16a, b.
  • the fiber molded body is fixed in the mold either by core parts or preferably by magnets - as shown in FIG. 3, the fibers additionally having to contain ferromagnetic metal parts.
  • the vacuum channel 9 is connected in the area of the casting run 8 between the end of the filling chamber 1 and the mold cavity 7. It can be formed from one line or preferably from a plurality of lines with a thin cross-section.
  • the mold cavity 7 can be evacuated to the exit side via a ring line 14. In the case of preheated fiber molded articles in particular, this ensures that volatile contaminants and gaseous inclusions of the fibers are extracted.
  • melt is drawn from the container 5 into the filling chamber 1 via the riser pipe 4.
  • the final pressure is in the range of 100 mbar - preferably between 95 and 110 mbar.
  • the evacuation time is set in the range of 2-10 seconds via a vacuum valve 11.
  • the pressure piston 2 then shoots the melt into the mold at a speed of 0.3 to 6 m / sec.
  • the mold 6a, b or 16a, b opens, so that the casting can be removed and the release agent can be sprayed on again for the next shot.
  • FIGS. 4 to 6 show 3 fiber-reinforced castings produced in different ways.
  • Fig. 4 shows a casting which was produced by conventional vacuum die casting technology, the vacuum channel being connected at the upper end of the mold cavity behind the fiber insert.
  • FIG 5 shows a fiber-reinforced die-cast part which was produced using a modified vacuum die-casting technique, the vacuum being drawn off in the region of the casting run and at the upper end of the mold cavity behind the fiber insert.
  • FIG. 6 shows a fiber-reinforced die-cast part which was produced by the method according to the invention with a vacuum connection in the region of the casting run.
  • the casting data for all three manufacturing processes are: Alloy: AlSi12CuNiMg according to DIN 1725, sheet 2 Casting temperature: 730 ° C Molding temperature: 200 - 250 ° C Shaped fiber: preheated from Al2O3 to> 650 ° C Casting pressure: varied between 980 and 1020 bar. After removal, the castings were cooled in air and solution-annealed at 500 ° C for one hour. This was followed by quenching in hot water with subsequent aging at 180-250 ° C. for 4 hours.
  • the casting shown in FIG. 4 has micro voids with diameters of 10 to 200 ⁇ m and gas-filled pores which contain residual gases from the atmosphere and vaporous parts of the lubricant.
  • the porosity of this part was more than 1.5%, calculated from the difference between the actual density and the theoretical density.
  • Parts from the manufacturing process described in connection with FIG. 5 have porosities between 0.5 and 1.0%. It can be seen that very many gaseous inclusions are still present, particularly in the fiber inserts.
  • the porosity of a casting produced by the process according to the invention was less than 0.3%.
  • the structure is homogeneous and without defects.
  • FIG. 7 shows a relatively uniform magnesium distribution between the fibers 27, 28, while in FIG. 8 an annular reaction layer 29 around the Al 2 O 3 fibers after a heat treatment of 500 ° C. for 3.5 hours and a subsequent quenching with hot water 30 was created.
  • the reaction layer in the example chosen here consists of AlMg spinels of the MgO ⁇ Al2O3 type, which increase the adhesion between the matrix and the fibers by a chemical bond by a factor of 2 to 10, the higher values with a subsequent aging at 200 ° C. for 4 hours were achieved.
  • a fiber-reinforced die-cast part produced by the process described above consists of a matrix made of a hardenable aluminum alloy with at least one addition of reactive elements from the group beryllium, calcium, magnesium, strontium and barium in contents of 0.1 to 5% by weight and fibers Alpha and / or delta alumina. It is advantageous if each fiber is surrounded by a reaction layer of mixed oxides of Al2O3 with the alloying elements of the Al alloy.
  • the reaction layer consists of the spinel MgO ⁇ Al2O3 and advantageously has a thickness of 0.1 to 5 ⁇ m.
  • a particular advantage of the method according to the invention is that hardenable aluminum alloys can also be used as the matrix material due to the large absence of pores. So far, the high temperatures required during curing have caused the structure to be expanded by gaseous inclusions and micro-cavities in such a way that large cracks and bubbles have formed on the surface.
  • the method according to the invention not only can the embedding of the fibers be improved by means of a reactive intermediate layer, but at the same time the strength of the matrix itself and thus the overall strength of the composite material can be increased.
  • FIGS. 9 to 11 show X-ray radiographs on a 1: 1 scale of fiber-reinforced connecting rods, three different production methods being used analogously to FIGS. 4 to 6.
  • the part in Fig. 9 was manufactured using conventional vacuum die casting technology, the vacuum channel being connected at the upper end of the mold cavity behind the fiber insert. 5, a modified vacuum die-casting process was used, in which the vacuum in the region of the casting run and at the upper end of the mold cavity behind the fiber insert was removed simultaneously.
  • the part in FIG. 11 was produced by the method according to the invention with a vacuum connection in the area of the casting run. The casting data have been explained in more detail in connection with FIGS. 4 to 6.
  • FIG. 9 shows numerous gas pores and voids in the area of the sprue, while only individual pores can be seen in the shaft area. According to FIG. 10, there are still some gas pores and cavities in the area of the connecting rod bearing, while in FIG. 11 this point no longer has any irregularities.
  • the irregularities (blowholes and glass bubbles) in the structure are starting points for cracks, which lead to a weakening of the strength values, in particular the notched impact strength. Comparative studies show that the strength decreases approximately in proportion to the amount of pore volume.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture Of Alloys Or Alloy Compounds (AREA)

Claims (9)

  1. Procédé de fabrication de pièces coulées en aluminium renforcées par des fibres par la technique de la coulée sous pression sous vide dans une machine de coulée sous pression à chambre froide horizontale, composée d'une chambre de remplissage (1) munie d'un piston d'injection (2) et d'au moins une empreinte (7) qui est reliée à la chambre de remplissage (1) par l'intermédiaire d'un canal d'injection (8), procédé dans lequel un vide est entretenu dans la chambre de remplissage et dans l'empreinte (7) avant ou pendant le remplissage du moule, caractérisé en ce que le vide régnant dans la région du canal d'injection (8) présente une plus faible pression gazeuse que dans le volume intérieur de l'empreinte (7) et une plus faible pression gazeuse que dans le volume intérieur de la chambre de remplissage (1).
  2. Procédé selon la revendication 1, caractérisé en ce que, immédiatement avant l'entrée du métal fondu dans le canal d'injection (8), la pression est de 50 à 100 mbar au raccordement de vide du canal d'injection (8) et de 100 à 150 mbar dans l'empreinte (7).
  3. Procédé selon une des revendications précédentes, caractérisé en ce que, pour assurer la formation d'une couche réactionnelle (29) entre les fibres (27, 28) et la matrice après l'achèvement de l'évacuation, la pièce coulée renforcée par des fibres est portée à une température de 450 à 550°C pendant 0,5 à 5 secondes et ensuite trempée à l'eau chaude.
  4. Pièce coulée sous pression renforcée de fibre, composée d'une matrice d'un alliage d'aluminium durcissable et de fibres d'oxyde d'aluminium alpha et/ou delta, caractérisée en ce que la matrice présente une addition d'éléments réactionnels du groupe béryllium, calcium, magnésium, strontium et baryum, à des teneurs de 0,1 à 5 % en poids et que les fibres sont entourées d'une couche réactionnelle d'une épaisseur de 0,1 à 5 µm.
  5. Pièce coulée sous pression selon la revendication 4 , caractérisée en ce que chaque fibre (27, 28) est entourée d'une couche réactionnelle (29) faite d'oxydes mixtes de Al₂O₃ et des éléments d'alliage de l'alliage d'aluminium.
  6. Pièce coulée sous pression selon une des revendications précédentes, caractérisée en ce que la couche réactionnelle (29) est composée de la spinelle MgO × Al₂O₃.
  7. Installation pour la fabrication de pièces coulées métalliques renforcées par des fibres par la technique de la coulée sous pression sous vide, comprenant une chambre de remplissage (1) munie d'un piston d'injection (2) dans des demi-moules (6a, b), l'empreinte (7), le canal d'injection (8) et un canal de vide (9), caractérisée en ce que le canal de vide (9) est agencé dans la région du canal d'injection (8), entre la chambre de remplissage (1) et l'empreinte (7).
  8. Installation selon une des revendications précédentes, caractérisée en ce que le raccordement du canal de vide (9) se produit dans la région du canal d'injection qui est la plus proche de la chambre de remplissage (1).
  9. Installation selon une des revendications précédentes, caractérisée en ce qu'en supplément du canal de vide (9), il est prévu d'autres canaux de vide (14a, b, c) dans la région d'entrée de l'empreinte (7).
EP87117752A 1987-01-17 1987-12-01 Procédé et installation pour la fabrication de pièces métalliques renforcées par des fibres Expired - Lifetime EP0275426B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT87117752T ATE68732T1 (de) 1987-01-17 1987-12-01 Verfahren und vorrichtung zur herstellung von faserverstaerkten metallteilen.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19873701218 DE3701218A1 (de) 1987-01-17 1987-01-17 Verfahren und vorrichtung zur herstellung von faserverstaerkten metallteilen
DE3701218 1987-01-17

Publications (3)

Publication Number Publication Date
EP0275426A2 EP0275426A2 (fr) 1988-07-27
EP0275426A3 EP0275426A3 (en) 1988-11-23
EP0275426B1 true EP0275426B1 (fr) 1991-10-23

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EP87117752A Expired - Lifetime EP0275426B1 (fr) 1987-01-17 1987-12-01 Procédé et installation pour la fabrication de pièces métalliques renforcées par des fibres

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EP (1) EP0275426B1 (fr)
AT (1) ATE68732T1 (fr)
DE (2) DE3701218A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108356249A (zh) * 2018-03-14 2018-08-03 马鞍山市万兴耐磨金属制造有限公司 一种基于水冷循环的铸铁降温冷却结构装置

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3903310C2 (de) * 1989-02-04 1992-10-22 Mahle Gmbh Verfahren zur herstellung eines mit einem porösen nachtraeglich auslösbaren einlageteil zu versehenden formgussteiles aus insbesondere aluminium.
JPH03230855A (ja) * 1990-02-05 1991-10-14 Yamazaki Kosakusho:Kk ダイカストの真空鋳造法
DE4418750C2 (de) * 1994-05-28 2000-06-15 Vaw Ver Aluminium Werke Ag Verfahren zur Herstellung von verschleißfesten Oberflächen auf Formgußteilen
JP3212245B2 (ja) * 1995-08-30 2001-09-25 マツダ株式会社 鋳造方法及び鋳造装置並びに鋳造品
CN104259430B (zh) * 2014-10-21 2016-03-30 湖南航天诚远精密机械有限公司 金属及其合金真空压铸成形装备及方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3404092C1 (de) * 1984-02-07 1985-06-13 Daimler-Benz Ag, 7000 Stuttgart Verfahren zur Herstellung faserverstaerkter Leichtmetallgussstuecke durch Druckgiessen
JPS61158884A (ja) * 1984-12-28 1986-07-18 宇部興産株式会社 溶融体含浸方法およびその装置
DE3504118C1 (de) * 1985-02-07 1985-10-31 Daimler-Benz Ag, 7000 Stuttgart Verfahren zur Herstellung faserverstaerkter Leichtmetall-Gussstuecke

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108356249A (zh) * 2018-03-14 2018-08-03 马鞍山市万兴耐磨金属制造有限公司 一种基于水冷循环的铸铁降温冷却结构装置

Also Published As

Publication number Publication date
EP0275426A2 (fr) 1988-07-27
DE3774105D1 (de) 1991-11-28
DE3701218A1 (de) 1988-07-28
EP0275426A3 (en) 1988-11-23
ATE68732T1 (de) 1991-11-15

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