US3228074A - Casting mold and method of making same - Google Patents
Casting mold and method of making same Download PDFInfo
- Publication number
- US3228074A US3228074A US260992A US26099263A US3228074A US 3228074 A US3228074 A US 3228074A US 260992 A US260992 A US 260992A US 26099263 A US26099263 A US 26099263A US 3228074 A US3228074 A US 3228074A
- Authority
- US
- United States
- Prior art keywords
- mold
- weight
- oxide
- mixture
- casting
- 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
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Classifications
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/06—Permanent moulds for shaped castings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/06—Permanent moulds for shaped castings
- B22C9/061—Materials which make up the mould
-
- 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
- B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
- B22F5/007—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of moulds
Definitions
- the molds were impervious to the gases generated by the casting process and frequently resulted in the formation of bodies with gas-containing cavities.
- Another disadvantage of these earlier method molds was that they readily adhered to the cast article, an occurrence which was only partly obviated by the coating of the mold cavities with a ceramic material.
- Still another object of the invention is to provide a method of making such a mold.
- a mold of exceptionally long life can be produced by sintering together a mixture of metallic particles and refractory particles at a temperature suificient to cause fusion of the particles without, however, closing interstitial passages which communicate with the mold cavity and permit the diffusion of gases away from this cavity.
- the sintered mixture is disposed at least in the region of the latter although it preferably occupies the entire mold bodies.
- the resulting metalloceramic body has excellent rigidity and can be formed by compounding the metallic particles with a refractory material in the presence of a binder adapted to impart stiffness to the mixture sufiicient to enable it to be molded and subsequently sintered.
- the metallic particles may be composed of iron or an iron alloy, with the refractory particles composed of a ceramic or graphite.
- the ceramic is preferably a high-melting-point metal oxide such as an alumina-containing substance, finely ground quartzite, zirconium oxide or chromium oxide and is present in an amount up to, say, 10% by weight of the mixture, the total amount of the refractory material ranging between substantially 5 and 25% by weight.
- the mold be passive with respect to the cast-ing metal so that a fusion is not possible.
- This passivity can be insured if the refractory fraction contains from 5 to 15% graphite.
- the binder may, advantageously, be a phenolic resin which constitutes between 0.2 and 5% by weight of the mixture prior to sintering, although other organic binders decomposable to carbon or even elemental carbon (in the form of charcoal) may be used.
- the binding effect can be prolonged after the sintering step if the binder is such that it only partly vaporizes during sintering with most of the remainder being released upon contact of the liquid metal with the mold material.
- a compacting of the mixture takes place at an elevated pressure between, say, 500 and 3000 kg./cm.
- This pressure can be applied prior to, with, or even possibly immediately after sintering mechanically or with the aid of an elevated ambient gas pressure.
- the pressure can be applied together with the molding step or thereafter without damage to the mold cavity.
- the mixture may include relatively low-boiling point components, including the binder, which are vaporized to leave voids constituting interstitial passages for the escape of gases.
- exothermically active materials can be included so that the heat generated by their reaction supplements that provided for sintering, it is thus possible to carry out the fusion step at a temperature much lower than would otherwise be possible.
- Suitable exothermic materials include metallic polysulphides and metal oxides capable of reacting with these sulphides to form volatile sulphur oxides.
- molybdenum disulphide in intimate mixture with metal oxides such as iron and manganese oxides is suitable.
- the volatile constituent should, however, be present in a particle size less than about microns while the sintered components have a particle size on the order of several hundred microns or greater.
- the refractory material chosen should be determined by the maximum temperature at which these materials retain their refractory proper-ties.
- quartzite is capable of withstanding temperatures up to 1700 C., while alumina-containing substances are refractory up to 1800 or 2000 C., while graphite is unaffected by heat up to substantially 3600 C.
- the mold body thus has a resistance to heat far greater than the temperature of liquid gray cast iron and malleable cast iron.
- the present invention also provides for the disposition of ceramic materials in the moldcavity regions of a sintered-metal porous mold body.
- a mold produced in accordance with the method described above is pervious to the gases normally developed during the casting process as well as those derived from sand cores and is capable of reproducing articles having a high definition. Moreover, the conventional manipulations of foundry sand are entirely avoided so that the casting process can be carried out with recycling of the molds.
- FIG. 1 is a cross-sectional view showing a separable mold provided with a sand core in accordance with the invention.
- FIG. 2 is a perspective view of a system for casting metallic articles with the aid of a mold of this type.
- FIG. 1 there is shown a bipartite mold whose cope half 10a and drag half 10b together define a mold cavity 13 in which a conventional sand core 14 is positioned.
- a pouring spout 11 and vent 12 communicate between the mold cavity 13 and the exterior while pivot lugs 16 and 1'7 are provided on the mold halves for holding them in position.
- the mold halves may be formed by casting a mixture produced in accordance with either of the following examples and sintering this mixture at the temperature indicated.
- the lugs 16 and 17 can be embedded in the mold body during casting and are rigid therewith when the body cools.
- a plurality of angularly spaced molds 18 can be positioned upon a turntable 19 which is rotatable in the direction of the arrow 20 to carry these molds past the various stations.
- the mold halves 10a, 10b can be joined by slotted links 21, 22 which are articulated thereto at the lugs 16 and 17.
- Each mold is then closed and conveyed by the intermittently rotated turntable 19 to the pouring position B at which a liquid metal is introduced into the cavity 13 via the spout 11.
- the molten metal hardens at the cooling stations C and D, at the latter of which the mold is opened for removal of the article.
- This arrangement permits the permanent mold to be positioned near the casting apparatus and eliminates transportation of the mold boxes with their molten contents over large distances.
- Example I A gas-permeable casting mold for chromium-contain ing aluminum alloys and suitable for the production of door fittings is produced from a mixture consisting of 80 to 85% of said iron powder having a particle size on the order of several hundred microns, 10 to 15 weight-percent powdered natural graphite, 1 to 3% phenolic resin, 1 to 2% bauxite and 1 to 2% by weight of an exothermic mixture consisting of molybdenum disulphide and either iron oxide or manganese oxide in the stoichiometric proportions necessary for complete reaction of the sulphur. It should be noted that the mold mixture contains no chromium since liquid aluminum has a tendency to dissolve materials containing this metal.
- the mixture of powders is compacted under a pressure of 500 to 1000 kg./cm. during molding and is subsequently sintered to a temperature of 800 to 900 C. This temperature would not normally suflice for a sintering action in the absence of additional heat provided from the exothermic reaction.
- the porosity of the metallo-ceramic body is between 15 to
- the wall of the mold cavity is then treated with graphite.
- Graphite can also be supplied to the wall of this cavity prior to sintering, e.g. by dusting, so that during the sintering operation it becomes bonded to the remainder of the mold body.
- Example II A mold for the production of cast-iron parts is produced from a powdered mixture containing 80 to 85% by weight of a silicon-alloy iron powder, 8 to 12 weight-percent graphite, 3 to 5% chromium oxide (Cr O 1 to 3% phenolic resin and 1 to 3% of a polysulphide/ oxide mixture.
- the composition is shaped and compressed under a pressure of 800 to 1500 kg/cm. and then sintered at a temperature between 800 and 1000 C.
- the particles are compressed in a hot state and form a mold body having a porosity of 10 to 20%.
- the mold-cavity surfaces are dusted with chromium oxide and alumina prior to casting and, advantageously, before sintering.
- a method of making a casting mold for liquid metals comprising the steps of homogeneously admixing between substantially to by weight of a metallic powder predominantly constituted of iron, between substantially 1 and 3% by weight of a binder for the particles, between 1 and 3% by weight of an exothermically reactive component consisting of at least one metal oxide and at least one reducing agent therefor in stoichiometrically equivalent quantities for reaction to produce a stoichiometric equivalent of gaseous products, and at least one comminuted refractory material selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, chromium oxide and graphite in an amount constituting the balance of the mixture; shaping the resulting mixture to form a mold body provided with a casting cavity at an elevated pressure between substantially 500 and 3000 kg./cm. and sintering said body at a temperature between substantially 800 and 1000 C. to react said oxide and said reducing agent and render said body coherent while forming therein interstitial passages for the escape of gases
- a method of making a casting mold for liquid metals comprising the steps of homogeneously admixing between substantially 80 to 85% by weight of a metallic powder predominantly constituted of iron, between substantially 1 and 3% by weight of a phenolic resin binder, between 1 and 3% by weight of an exothermically reactive compoent consisting of at least one metal oxide and at least one metal-polysulphide reducing agent therefor in stoichiometrically equivalent quantities, and at least one comminuted refractory material selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, chromium oxide and graphite in an amount constituting the balance of the mixture; shaping the resulting mixture to form a mold body provided with a casting cavity at an elevated pressure between substantially 500 and 3000 kg./ cm?; and sintering said body at a temperature between substantially 800 and 1000 C. to render said body coherent with a porosity between 10 and 30%, and form therein interstitial passages for the escape of gases from said cavity.
- a method of making a casting mold for liquid metals comprising the steps of homogeneously admixing between substantially 80 to 85 by weight of a metallic powder predominantly constituted of iron, between substantially 1 and 3% by weight of a phenolic resin binder, between 1 and 3% by weight of a particulate exothermically reactive component consisting of at least one metal oxide and at least one metal-polysulphide reducing agent therefor in stoichiometrically equivalent quantities and a maximum particle size of microns, and at least one comminuted refractory material selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, chromium oxide and graphite in an amount constituting the balance of the mixture; shaping the resulting mixture to form a mold body provided with a casting cavity at an elevated pressure between substantially 500 and 3000 kg./cm.
- said layer is an oxide selected from the group consisting of aluminum oxide and chromiumoxide.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Agricultural Chemicals And Associated Chemicals (AREA)
- Mold Materials And Core Materials (AREA)
Description
Claims (1)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DED0038249 | 1962-02-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3228074A true US3228074A (en) | 1966-01-11 |
Family
ID=7044009
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US260992A Expired - Lifetime US3228074A (en) | 1962-02-27 | 1963-02-26 | Casting mold and method of making same |
Country Status (2)
Country | Link |
---|---|
US (1) | US3228074A (en) |
DE (1) | DE1458270A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5232610A (en) * | 1989-09-15 | 1993-08-03 | Mclaughlin Timothy M | Mold element construction |
US20070139136A1 (en) * | 2005-12-15 | 2007-06-21 | Yung-Chin Chen | Housing of satellite receiver and method for forming the same |
Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB696301A (en) * | 1948-12-21 | 1953-08-26 | Buderus Eisenwerk | Moulds for casting metals, particularly steel and iron |
GB701541A (en) * | 1950-07-22 | 1953-12-30 | Buderus Eisenwerk | Moulds for casting metals, particularly steel and iron |
GB714560A (en) * | 1952-11-13 | 1954-09-01 | Thompson Prod Inc | Improvements in or relating to method of making porous sintered articles |
US2792302A (en) * | 1955-08-29 | 1957-05-14 | Connecticut Metals Inc | Process for making porous metallic bodies |
US2848324A (en) * | 1954-04-30 | 1958-08-19 | Krapf Siegfried | Method of producing agglomerates highly resistant against heat and/or chemical attack |
US2857270A (en) * | 1950-12-27 | 1958-10-21 | Hoganas Billesholms Ab | Method for the production of metal powder for powder metallurgical purposes |
US2870497A (en) * | 1956-08-13 | 1959-01-27 | Strauss | Casting metals and alloys |
US2979400A (en) * | 1959-02-04 | 1961-04-11 | Purolator Products Inc | Porous media |
US2982014A (en) * | 1955-05-20 | 1961-05-02 | Meyer-Hartwig Eberhard | Process of manufacturing ceramic compounds and metallic ceramic compounds |
DE1110368B (en) * | 1957-01-04 | 1961-07-06 | Oesterr Amerikan Magnesit | Lining compound for foundry purposes |
US3158473A (en) * | 1962-08-27 | 1964-11-24 | Gen Electric | Method for producing composite bodies |
-
1962
- 1962-02-27 DE DE19621458270 patent/DE1458270A1/en active Pending
-
1963
- 1963-02-26 US US260992A patent/US3228074A/en not_active Expired - Lifetime
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB696301A (en) * | 1948-12-21 | 1953-08-26 | Buderus Eisenwerk | Moulds for casting metals, particularly steel and iron |
GB701541A (en) * | 1950-07-22 | 1953-12-30 | Buderus Eisenwerk | Moulds for casting metals, particularly steel and iron |
US2857270A (en) * | 1950-12-27 | 1958-10-21 | Hoganas Billesholms Ab | Method for the production of metal powder for powder metallurgical purposes |
GB714560A (en) * | 1952-11-13 | 1954-09-01 | Thompson Prod Inc | Improvements in or relating to method of making porous sintered articles |
US2848324A (en) * | 1954-04-30 | 1958-08-19 | Krapf Siegfried | Method of producing agglomerates highly resistant against heat and/or chemical attack |
US2982014A (en) * | 1955-05-20 | 1961-05-02 | Meyer-Hartwig Eberhard | Process of manufacturing ceramic compounds and metallic ceramic compounds |
US2792302A (en) * | 1955-08-29 | 1957-05-14 | Connecticut Metals Inc | Process for making porous metallic bodies |
US2870497A (en) * | 1956-08-13 | 1959-01-27 | Strauss | Casting metals and alloys |
DE1110368B (en) * | 1957-01-04 | 1961-07-06 | Oesterr Amerikan Magnesit | Lining compound for foundry purposes |
US2979400A (en) * | 1959-02-04 | 1961-04-11 | Purolator Products Inc | Porous media |
US3158473A (en) * | 1962-08-27 | 1964-11-24 | Gen Electric | Method for producing composite bodies |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5232610A (en) * | 1989-09-15 | 1993-08-03 | Mclaughlin Timothy M | Mold element construction |
US5722038A (en) * | 1989-09-15 | 1998-02-24 | Mclaughlin; Timothy M. | Mold element construction and related method |
US20070139136A1 (en) * | 2005-12-15 | 2007-06-21 | Yung-Chin Chen | Housing of satellite receiver and method for forming the same |
US7459994B2 (en) * | 2005-12-15 | 2008-12-02 | Wistron Neweb Corporation | Housing of satellite receiver and method for forming the same |
Also Published As
Publication number | Publication date |
---|---|
DE1458270A1 (en) | 1968-12-19 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: DEVENTER-WERKE KOMMANDITGESELLSCHAFT Free format text: CHANGE OF NAME;ASSIGNOR:DEVENTER-WERKE GESELLSCHAFT MIT BESCHRANKTER HAFTUNG;REEL/FRAME:003841/0956 Effective date: 19710921 Owner name: GLACIER GMBH -DEVA WERKE, STADT ALLENDORF, DIST. O Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:DEVENTER WERKE KG.;REEL/FRAME:003851/0621 Effective date: 19750106 Owner name: AEX-ASSOCIATED EBNGINEERING ZUG, AG. , C/O PETERHA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:GLACIER GMBH-DEVA WERKE;REEL/FRAME:003851/0622 Effective date: 19780530 Owner name: DEVENTER-WERKE KOMMANDITGESELLSCHAFT, GERMANY Free format text: CHANGE OF NAME;ASSIGNOR:DEVENTER-WERKE GESELLSCHAFT MIT BESCHRANKTER HAFTUNG;REEL/FRAME:003841/0956 Effective date: 19710921 |