CA1064219A - Joining of multi-section ceramic molds - Google Patents
Joining of multi-section ceramic moldsInfo
- Publication number
- CA1064219A CA1064219A CA231,420A CA231420A CA1064219A CA 1064219 A CA1064219 A CA 1064219A CA 231420 A CA231420 A CA 231420A CA 1064219 A CA1064219 A CA 1064219A
- Authority
- CA
- Canada
- Prior art keywords
- mold
- ring
- assembled
- holding device
- ceramic
- 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
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
- B22D27/04—Influencing the temperature of the metal, e.g. by heating or cooling the mould
- B22D27/045—Directionally solidified castings
Abstract
ABSTRACT OF THE DISCLOSURE
The several mating preformed parts of a multi-part ceramic mold are held in assembled relation by a surround-ing ring that closely engages the mold. The ring may be slid over the mold or may be formed in place on the mold to be in intimate contact therewith and become a permanent part of the mold. The ring may have an integral pouring cup if the ring is to be at the top of the mold.
The several mating preformed parts of a multi-part ceramic mold are held in assembled relation by a surround-ing ring that closely engages the mold. The ring may be slid over the mold or may be formed in place on the mold to be in intimate contact therewith and become a permanent part of the mold. The ring may have an integral pouring cup if the ring is to be at the top of the mold.
Description
BACKGROUND OF THE INVENTION
Field of the Invention - This invention relates to the casting of colu~nar grained or equiaxed articles particularly from high temperature alloys in a multi-part mold made up of a plural-ity of mold elements. Such articles may be conventionally cast or columnar grained or may be caqt from some of the eutectics.
SUMMARY, OF THE INVENTICN
The preformed or precast parts of a multi-part ld as described in applicants' copending application Serial No. 210,674, filed July 4, 1975 must be held together ~ecurely in a-~sembled relation when the mold is poured to assure no leakage from the mold and to assure the de~ired precision in the finished casting.
The securing means must be able to withstand the heat to which the mold is heated which, in columnar grain ca~ting, for ex-ample, is a temperature above the melting point of the alloy. Thus ~ ~
metallic clamp~ are not readily usable, The clamp mu~t have ther~al~ ;
characteristicA similar to those of the mold, such as the co-efficient of thermal expansion, to avoid localized stressing of ~
either the mold or the clamp. ~ -According to the invention, a high strength ceramic ring ` ;~
is po-~itioned around the multi-part mold at one or more locations ~-along its length, the ring being a close fit to the outer sur-faces o~ the ld in order to hold ,;' :.
.;
Field of the Invention - This invention relates to the casting of colu~nar grained or equiaxed articles particularly from high temperature alloys in a multi-part mold made up of a plural-ity of mold elements. Such articles may be conventionally cast or columnar grained or may be caqt from some of the eutectics.
SUMMARY, OF THE INVENTICN
The preformed or precast parts of a multi-part ld as described in applicants' copending application Serial No. 210,674, filed July 4, 1975 must be held together ~ecurely in a-~sembled relation when the mold is poured to assure no leakage from the mold and to assure the de~ired precision in the finished casting.
The securing means must be able to withstand the heat to which the mold is heated which, in columnar grain ca~ting, for ex-ample, is a temperature above the melting point of the alloy. Thus ~ ~
metallic clamp~ are not readily usable, The clamp mu~t have ther~al~ ;
characteristicA similar to those of the mold, such as the co-efficient of thermal expansion, to avoid localized stressing of ~
either the mold or the clamp. ~ -According to the invention, a high strength ceramic ring ` ;~
is po-~itioned around the multi-part mold at one or more locations ~-along its length, the ring being a close fit to the outer sur-faces o~ the ld in order to hold ,;' :.
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the mold part~ in proper assembled relation. The ring may be a close slidable fit or it may be formed on the assembled mold parts to be essentially an integral part of the mold. The ring may be separately formed to be positioned around the mold or cast around the assembled mold or formed by the ~hell molding process in dipping a part of the mold in a ceramic slurry and drying the coating of ceramic formed thereon, the dipping and drying proce-~s being repeated until a coating of the desired ~trength i8 obtained.
According to one feature the ring may have an integral pouring cup if the ring is positioned at the top of the mold. As an alternative to the ring, high strength ceramic clip or holding means may be positioned over the mating flanges of the mold parts.
In accordance with one embodiment, a holding device for use with a multi-part mold for the casting of high temperature - -metal alloys, said mold including: opposed precast ceramic mold sides having projecting matting edge flanges and having recesses therein to form an article cavity comprises; a high strength ceramic ring tightly surrounding the opposed mold sides and en-gaging the edge flanges to hold the opposed sides together, said ring extending a part only of the length of the mold sides and said ring having a compatible thermal expdnsion to that of the mold sides.
The invention also relates to a multi-part mold includ-ing at least opposed ceramic ~ide plates with projecting edge flanges having cooperating surfaces to hold the side plates in assembled casting position, and means surrounding the side plates for a portion of the length of the mold to hold the plates to-gether, said means being a high strength ceramic ring extending completely around the a~sembled mold and having an inner surface conforming to substantially the outer surfaces of the projecting edge flanges of the side plates of the mold engaged thereby to hold the oppo3ed side plate~ in casting position, said ring being of a material having a thermal expansion compatible with the mold ~;
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From a different aspect, in accordance with the inven-tion, there i~ provided, in the attachment of prefonmed ceramic ~old parts together, said mold parts having mating edge flanges, the steps of, dipping at least a part of the assembled ld elements including a part of the edge flanges in a ceramic slurry of the shell mold type to form a coating in the form of a ring thereon: drying the coating, and repeating the dipping and drying until a holding ring of the desired thickness i8 obtained.
The foregoing and other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of preferred embodiments ~ -thereof a~ illustrated in the accompanying drawing~.
BRIEF DES RIPTION OF THE DRAWINGS
Fig. 1 is an elevation of a mold with a holding ring -of the invention in position.
Fig. 2 is a sectional view along line 2-2 of Fig. 1.
Fig. 3 is a elevation of-a ld as in Fig~ 1 with a modified form of holding ring. ~
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Fig. 4 is a ~ectional view along line 4-4 of Fig. 3.
~ ig. 5 is an elevation of a mold with other forms of rings thereon.
Fig. 6 i~ a sectional view along line 6-6 of Fig. 5.
Fig. 7 is a fragmentation elevation of the top of the mold with a modified form of the ring of Fig. 1, with parts broken away to show the con~truction. ,~
Fig. 8 is a view similar to Fig. 7 of a modificatlon of the ring of Fig. 5. -; Fig. 9 is a further modification shown in elevation.
Fig. 10 is a sectional view along line 10-10 of Fig. 9.
DESCRIPTIO~ OF THE PREFERRED EMBoDIMENT
Referring first to Figs. 1 and 2 the preformed multi-part mold is shown by way of example for making the opposed halves of a turbine blade as described and claimed in the copending ~-application Serial No. 210,674 above identified. The mold includes preformed opposed mold sides 10 and 12 of a suitable -ceramic and center divider 14 also of a ceramic. ~he divider has ,~
edge flanges 16 and 18 received in notches in cooperating edge flanges 20 and 22 on one edge of sides 10 and 12 and other co- , operating edge flanges 24 and 26 on the opposite edges of sides `,~ `
10 and 12.
The molds sides 10 and 12 may have hold down flanges 28 at one end by which the mold, when assembled is held in position on a chill plate. Although the mold has other ;
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10~;4Z19 uses, such ~ mold construct~on is particularly useful in casting columnar grained articles of the type claimed in VerSnyder 3,260,505 or Piearcey 3,494,707. The latter single crystal cast article is a particular form of columnar grain. This type of mold is also usable in casting eutectics such as described in Gell 3,567,526, which are also columnar grained.
Such molds must be held in secure assembled arrangement during the casting operation and the holding device must be such as not to be destroyed by the step of heating the mold to a temperature above the melting point of the alloy and also such as not to be overstressed ar to overstress the mold parts during the heating operation or during the sub-sequent relatively fast cooling.
To accomplish this, the mold parts are surrounded at ~ -the desired location lengthwise of the mold parts by a ceramic ~
ring 32 cast of high strength ceramic material. This ring ~-~ has an inner surface 34 the contour of which closely fits ; the outer surfaces of the mold parts, at least at the mating flanges 20 and 22 at one edge and the opposite -` -~; mating flanges 24 and 26. There is just enough clearance "~ -to perm~t the ring to sLide down over the assembled mold to the desired portion on the mold. Although the inner surface of the ring i8 shown as closely fitting over the entire area of the mold ad~acent thereto, it is obvious that the partic-ulsr close fit i8 at the mating flanges. For this type of .: . ,':`' . - ,'', ' .:
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1064Z~9 ring to be usable the mold must be the same size or smaller from the ring area to the top of the mold so that the ring may slide into position. Once the ring is in place it may be additionally secured by a suitable cement, not shown.
In the arrangement shown the mold has an enlargement 34 near the base to form the root portion of the blade, above which is the airfoil portion 36 of the mold and the ring 32 is shaped to fit the mold at the enlargement 34 as shown. The cast articles are formed in the mold cavities 37 and 38.
As an alternate to the ring of Figs. 1 and 2, the holding ring may be molded around the mold as in Figs. 3 and 4. In this arrangement the mold parts 42 and 44 have the mating edge flanges 46 and 48 and the enlarged root portion 50 below the airfoil portion 52. This mold con-struction also has a shroud area 54 at the top of the airfoil portion such that the sliding ring of Figs. 1 and 2 cannot be used. Instead, the ring 56 is formed in a ring mold, not shown, positioned around the mold. Moldable ;-high strength ceramic is packed in the ring mold to form ~-the ring 56 and, after suitable hardening by heating mold and ring, the ring mold is removed to produce the structure shown. Here the inner surface 58 of the ring is in intimate . ~ .....
and permanent engagement with the mold parts 42 and 44. -Thus these mold parts are held in secure engagement with ', --6-- : ~
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~" ; : - . , each other during the casting operation. The material of ring 56 may obviously be any of the known high strength moldable ceramics and not necessarily the same material as the ceramic mold parts 42 and 44. By using different materials, the differential thermal expansion may be used to enhance the clamping action. The ring may be located at any position desired lengthwise of the mold. More than one of these rings may frequently be helpful in holding the mold parts securely together, such as the second ring 58 at the top of the mold.
Another form of holding ring for the multi-part mold is shown in Figs. 5 and 6. Here the mold sides 62 and 64 with mating edge flanges 66 and 68 and a central mold divider 70 are held together at top and bottom by rings 72 and 74, the latter enclosing the bottom flanges 76.
Each of these rings is formed by suitably holding the mold parts together between the ends as by a stretchable ~ -band, not shown, around the non-ceated portion. Each end is then dipped in a ceramic slurry to form a coating, and then dried, with the dipping and drying being repeated enough times to produce the desired thickness of coating - ~
to form a ring of adequate strength around the mold. ~ - -1 After each dipping the wet dip coat may be coated with I a granular ceramic. This is the procedure~used to form -` -' a shell mold and after the desired ring thickness i8 I obtained, the mold with the rings thereon is baked as ~
- -in an oven to cure the material of the rings. In this way a suitable holding ring is produced with adequate strength to hold the mold parts in place for a casting operation.
To prevent the inner mold cavities from being con-taminated by the slurry in making the rings 72 and 74 the ends of the mold assembly may be temporarily closed as by a sheet of ¢ardboard or the like adhered thereto. Either ring 72 or 74 may be formed independently of the other and only one ring may be used in certain mold structures.
In any event the holding rings are securely attached to and form a permanent connection with the molds. The ring material is removed from the cast articles in the same manner as the mold material.
The slidable ring of Figs. 1 and 2 may be modified, if placed on the top end of the mold as in Fig. 7. Thus the ring 80, slidably mounted on the top end of the multi- ~-part mold 82, has an integral filler cup 84 cast with the ring. The cup forms a shoulder 85 that limits the position of the ring o* the mold. The cup receives the molten alloy -when the mold i8 being poured.and directs it into the mold.
The ring thus serves both to hold the mold parts in assembled relation and as a filler cup. The ring and filler cup are `-molded into the configuration shown and baket to harden :. -~the ceramic before positioning them on the mold a~embly~ ~
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~064219 Instead of a ring and integral filler cup positionable on the mold, the ring may be formed on the mold by the shell molding process. Thus as in Fig. 8, a shell mold type of coating 86 is formed on the upper end of the mold 88, but in this arrangement a wax pattern 89 positioned on the top of the mold forms a filler cup 90 that is integral with the ring 92. Both elements 90 and 92 are simultaneously formed by dipping and drying the end of the mold as above described with reference to Figs. 5 and 6 until the desired thickness of ring is produced. The ring produced in this way becomes securely and permanently a part of the mold and performs its holding function while the mold is poured.
In some circumstances the presence of a surrounding ring as described may affect the cooling of the alloy after ~-~
the mold is poured. To avoid this the mold halves 92 and 94, ^
Figs. 9 and 10, may be held together by a shell mold type of coating located only along the mat~ng side flanges 96 a~d 98. To do this, these side flanges are repeatedly dipped `~' in a slurry for coating and then dried to build up a holding -~
clip 100 and 102 that overlies the edge flanges but does not cover the parts of the mold directly external to the ~i . :
part being cast. Again the material used i8 a high strength ceramic which is hardened as by baking after the desired ,~ ;, ~.
thickness is obtained thereby to obtain the desired strength.
Thege clip~ are essentially a permanent part of the assembled ~ ': ~' ., .
_9_ :
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, ~ ~ ~.: - , . . . . i , ' - . .. . ' ' `. ' -10~;4Z19 mold when the latter is ready to be used and serve to hold the opposed mold halves securely in desired relation during the casting operation, Although the drawings show a three-part mold in-cluding a center element, it is obvious that the invention is equally applicable to a two-part mold.
Although the invention has been shown and described with respect to a preferred embodiment thereof, it should be understood by those skilled in the art that various changes and omissions in the form and detail thereof may be made therein without departing from the spirit and the scope of the invention.
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the mold part~ in proper assembled relation. The ring may be a close slidable fit or it may be formed on the assembled mold parts to be essentially an integral part of the mold. The ring may be separately formed to be positioned around the mold or cast around the assembled mold or formed by the ~hell molding process in dipping a part of the mold in a ceramic slurry and drying the coating of ceramic formed thereon, the dipping and drying proce-~s being repeated until a coating of the desired ~trength i8 obtained.
According to one feature the ring may have an integral pouring cup if the ring is positioned at the top of the mold. As an alternative to the ring, high strength ceramic clip or holding means may be positioned over the mating flanges of the mold parts.
In accordance with one embodiment, a holding device for use with a multi-part mold for the casting of high temperature - -metal alloys, said mold including: opposed precast ceramic mold sides having projecting matting edge flanges and having recesses therein to form an article cavity comprises; a high strength ceramic ring tightly surrounding the opposed mold sides and en-gaging the edge flanges to hold the opposed sides together, said ring extending a part only of the length of the mold sides and said ring having a compatible thermal expdnsion to that of the mold sides.
The invention also relates to a multi-part mold includ-ing at least opposed ceramic ~ide plates with projecting edge flanges having cooperating surfaces to hold the side plates in assembled casting position, and means surrounding the side plates for a portion of the length of the mold to hold the plates to-gether, said means being a high strength ceramic ring extending completely around the a~sembled mold and having an inner surface conforming to substantially the outer surfaces of the projecting edge flanges of the side plates of the mold engaged thereby to hold the oppo3ed side plate~ in casting position, said ring being of a material having a thermal expansion compatible with the mold ~;
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; .. ~- ~,, : -10~4219 material.
From a different aspect, in accordance with the inven-tion, there i~ provided, in the attachment of prefonmed ceramic ~old parts together, said mold parts having mating edge flanges, the steps of, dipping at least a part of the assembled ld elements including a part of the edge flanges in a ceramic slurry of the shell mold type to form a coating in the form of a ring thereon: drying the coating, and repeating the dipping and drying until a holding ring of the desired thickness i8 obtained.
The foregoing and other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of preferred embodiments ~ -thereof a~ illustrated in the accompanying drawing~.
BRIEF DES RIPTION OF THE DRAWINGS
Fig. 1 is an elevation of a mold with a holding ring -of the invention in position.
Fig. 2 is a sectional view along line 2-2 of Fig. 1.
Fig. 3 is a elevation of-a ld as in Fig~ 1 with a modified form of holding ring. ~
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Fig. 4 is a ~ectional view along line 4-4 of Fig. 3.
~ ig. 5 is an elevation of a mold with other forms of rings thereon.
Fig. 6 i~ a sectional view along line 6-6 of Fig. 5.
Fig. 7 is a fragmentation elevation of the top of the mold with a modified form of the ring of Fig. 1, with parts broken away to show the con~truction. ,~
Fig. 8 is a view similar to Fig. 7 of a modificatlon of the ring of Fig. 5. -; Fig. 9 is a further modification shown in elevation.
Fig. 10 is a sectional view along line 10-10 of Fig. 9.
DESCRIPTIO~ OF THE PREFERRED EMBoDIMENT
Referring first to Figs. 1 and 2 the preformed multi-part mold is shown by way of example for making the opposed halves of a turbine blade as described and claimed in the copending ~-application Serial No. 210,674 above identified. The mold includes preformed opposed mold sides 10 and 12 of a suitable -ceramic and center divider 14 also of a ceramic. ~he divider has ,~
edge flanges 16 and 18 received in notches in cooperating edge flanges 20 and 22 on one edge of sides 10 and 12 and other co- , operating edge flanges 24 and 26 on the opposite edges of sides `,~ `
10 and 12.
The molds sides 10 and 12 may have hold down flanges 28 at one end by which the mold, when assembled is held in position on a chill plate. Although the mold has other ;
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10~;4Z19 uses, such ~ mold construct~on is particularly useful in casting columnar grained articles of the type claimed in VerSnyder 3,260,505 or Piearcey 3,494,707. The latter single crystal cast article is a particular form of columnar grain. This type of mold is also usable in casting eutectics such as described in Gell 3,567,526, which are also columnar grained.
Such molds must be held in secure assembled arrangement during the casting operation and the holding device must be such as not to be destroyed by the step of heating the mold to a temperature above the melting point of the alloy and also such as not to be overstressed ar to overstress the mold parts during the heating operation or during the sub-sequent relatively fast cooling.
To accomplish this, the mold parts are surrounded at ~ -the desired location lengthwise of the mold parts by a ceramic ~
ring 32 cast of high strength ceramic material. This ring ~-~ has an inner surface 34 the contour of which closely fits ; the outer surfaces of the mold parts, at least at the mating flanges 20 and 22 at one edge and the opposite -` -~; mating flanges 24 and 26. There is just enough clearance "~ -to perm~t the ring to sLide down over the assembled mold to the desired portion on the mold. Although the inner surface of the ring i8 shown as closely fitting over the entire area of the mold ad~acent thereto, it is obvious that the partic-ulsr close fit i8 at the mating flanges. For this type of .: . ,':`' . - ,'', ' .:
'~
1064Z~9 ring to be usable the mold must be the same size or smaller from the ring area to the top of the mold so that the ring may slide into position. Once the ring is in place it may be additionally secured by a suitable cement, not shown.
In the arrangement shown the mold has an enlargement 34 near the base to form the root portion of the blade, above which is the airfoil portion 36 of the mold and the ring 32 is shaped to fit the mold at the enlargement 34 as shown. The cast articles are formed in the mold cavities 37 and 38.
As an alternate to the ring of Figs. 1 and 2, the holding ring may be molded around the mold as in Figs. 3 and 4. In this arrangement the mold parts 42 and 44 have the mating edge flanges 46 and 48 and the enlarged root portion 50 below the airfoil portion 52. This mold con-struction also has a shroud area 54 at the top of the airfoil portion such that the sliding ring of Figs. 1 and 2 cannot be used. Instead, the ring 56 is formed in a ring mold, not shown, positioned around the mold. Moldable ;-high strength ceramic is packed in the ring mold to form ~-the ring 56 and, after suitable hardening by heating mold and ring, the ring mold is removed to produce the structure shown. Here the inner surface 58 of the ring is in intimate . ~ .....
and permanent engagement with the mold parts 42 and 44. -Thus these mold parts are held in secure engagement with ', --6-- : ~
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~" ; : - . , each other during the casting operation. The material of ring 56 may obviously be any of the known high strength moldable ceramics and not necessarily the same material as the ceramic mold parts 42 and 44. By using different materials, the differential thermal expansion may be used to enhance the clamping action. The ring may be located at any position desired lengthwise of the mold. More than one of these rings may frequently be helpful in holding the mold parts securely together, such as the second ring 58 at the top of the mold.
Another form of holding ring for the multi-part mold is shown in Figs. 5 and 6. Here the mold sides 62 and 64 with mating edge flanges 66 and 68 and a central mold divider 70 are held together at top and bottom by rings 72 and 74, the latter enclosing the bottom flanges 76.
Each of these rings is formed by suitably holding the mold parts together between the ends as by a stretchable ~ -band, not shown, around the non-ceated portion. Each end is then dipped in a ceramic slurry to form a coating, and then dried, with the dipping and drying being repeated enough times to produce the desired thickness of coating - ~
to form a ring of adequate strength around the mold. ~ - -1 After each dipping the wet dip coat may be coated with I a granular ceramic. This is the procedure~used to form -` -' a shell mold and after the desired ring thickness i8 I obtained, the mold with the rings thereon is baked as ~
- -in an oven to cure the material of the rings. In this way a suitable holding ring is produced with adequate strength to hold the mold parts in place for a casting operation.
To prevent the inner mold cavities from being con-taminated by the slurry in making the rings 72 and 74 the ends of the mold assembly may be temporarily closed as by a sheet of ¢ardboard or the like adhered thereto. Either ring 72 or 74 may be formed independently of the other and only one ring may be used in certain mold structures.
In any event the holding rings are securely attached to and form a permanent connection with the molds. The ring material is removed from the cast articles in the same manner as the mold material.
The slidable ring of Figs. 1 and 2 may be modified, if placed on the top end of the mold as in Fig. 7. Thus the ring 80, slidably mounted on the top end of the multi- ~-part mold 82, has an integral filler cup 84 cast with the ring. The cup forms a shoulder 85 that limits the position of the ring o* the mold. The cup receives the molten alloy -when the mold i8 being poured.and directs it into the mold.
The ring thus serves both to hold the mold parts in assembled relation and as a filler cup. The ring and filler cup are `-molded into the configuration shown and baket to harden :. -~the ceramic before positioning them on the mold a~embly~ ~
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~064219 Instead of a ring and integral filler cup positionable on the mold, the ring may be formed on the mold by the shell molding process. Thus as in Fig. 8, a shell mold type of coating 86 is formed on the upper end of the mold 88, but in this arrangement a wax pattern 89 positioned on the top of the mold forms a filler cup 90 that is integral with the ring 92. Both elements 90 and 92 are simultaneously formed by dipping and drying the end of the mold as above described with reference to Figs. 5 and 6 until the desired thickness of ring is produced. The ring produced in this way becomes securely and permanently a part of the mold and performs its holding function while the mold is poured.
In some circumstances the presence of a surrounding ring as described may affect the cooling of the alloy after ~-~
the mold is poured. To avoid this the mold halves 92 and 94, ^
Figs. 9 and 10, may be held together by a shell mold type of coating located only along the mat~ng side flanges 96 a~d 98. To do this, these side flanges are repeatedly dipped `~' in a slurry for coating and then dried to build up a holding -~
clip 100 and 102 that overlies the edge flanges but does not cover the parts of the mold directly external to the ~i . :
part being cast. Again the material used i8 a high strength ceramic which is hardened as by baking after the desired ,~ ;, ~.
thickness is obtained thereby to obtain the desired strength.
Thege clip~ are essentially a permanent part of the assembled ~ ': ~' ., .
_9_ :
:
, ~ ~ ~.: - , . . . . i , ' - . .. . ' ' `. ' -10~;4Z19 mold when the latter is ready to be used and serve to hold the opposed mold halves securely in desired relation during the casting operation, Although the drawings show a three-part mold in-cluding a center element, it is obvious that the invention is equally applicable to a two-part mold.
Although the invention has been shown and described with respect to a preferred embodiment thereof, it should be understood by those skilled in the art that various changes and omissions in the form and detail thereof may be made therein without departing from the spirit and the scope of the invention.
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Claims (22)
1. A holding device for use with a multi-part mold for casting of high temperature metal alloys, said mold including opposed precast ceramic mold sides having projecting mating edge flanges and having recesses therein to form an article cavity;
said holding device comprising:
a high strength ceramic ring tightly surrounding the opposed mold sides and engaging the edge flanges to hold the opposed sides together, said ring extending a part only of the length of the mold sides and said ring having a compatible thermal expansion to that of the mold sides.
said holding device comprising:
a high strength ceramic ring tightly surrounding the opposed mold sides and engaging the edge flanges to hold the opposed sides together, said ring extending a part only of the length of the mold sides and said ring having a compatible thermal expansion to that of the mold sides.
2. A holding device as in claim 1 in which the ceramic ring is integrally connected with the mold sides.
3. A holding device as in claim 1 in which the ring in-cludes a pouring cup.
4. A holding device as in claim 1 in which the ring is hardened after positioning on the mold sides.
5. In the attachment of preformed ceramic mold parts together, said mold parts having mating edge flanges, the steps of:
dipping at least a part of the assembled mold elements including a part of the edge flanges in a ceramic slurry of the shell mold type to form a coating in the form of a ring thereon;
drying the coating; and repeating the dipping and drying until a holding ring of the desired thickness is obtained.
dipping at least a part of the assembled mold elements including a part of the edge flanges in a ceramic slurry of the shell mold type to form a coating in the form of a ring thereon;
drying the coating; and repeating the dipping and drying until a holding ring of the desired thickness is obtained.
6. The process of claim 5 including the step of dipping both ends of the assembled mold elements to form a holding ring at each end.
7. The process of claim 5 including a first step of forming a pouring cup pattern on the end of the assembled mold parts, and then dipping and drying the pattern and the portion of the mold adjacent thereto to form a shell pouring cup integral with a hold-ing ring at the top of the mold parts.
8. The process of claim 5 in which the portions of the assembled mold elements to be coated are at least the outer side surfaces of the mating edge flanges.
9. The process of claim 5 in which the assembled mold elements have clamping flanges at an end and are open at that end to rest on a chill plate, and in which the flanges and adja-cent portions of the assembled mold elements are the areas of the mold elements to be treated by the process.
10. The holding device as in claim 1 wherein said ring has a inner surface conforming substantially to the cross-sectional shape of the mold within the ring.
11. A holding device as in claim 10 in which the ring is integrally bonded to the mold where the ring surrounds it.
12. A holding device as in claim 10 in which the ring is located at the top of the assembled multi-part mold and has a integral filler cup.
13. A holding device as in claim 12 in which the ring is slidable over the top of the mold.
14. A holding device as in claim 10 in which the mold is formed to be a least as small as the opening in the ring from the location where the ring is positioned to one end of the multi-part mold for placing the ring in position.
15. A holding device as in claim 10 in which the ring is formed by dipping the mold in part in a ceramic slurry and drying and hardening the dip coat.
16. A multi-part mold including at least opposed ceramic side plates with projecting edge flanges having cooperating surfaces to hold the side plates in assembled casting position, and means surrounding the side plates for a portion of the length of the mold to hold the plates together, said means being a high strength ceramic ring extending completely around the assembled mold and having an inner surface conforming to substantially the outer surfaces of the projecting edge flanges of the side plates of the mold engaged therby to hold the opposed side plates in casting position;
said ring being of a material having a thermal expansion compatible with the mold material.
said ring being of a material having a thermal expansion compatible with the mold material.
17. A multi-part mold as in claim 16 in which the ring is in bonded relation to the underlying surfaces of the mold.
18. A multi-part mold as in claim 16 in which the ring is slidable on the mold surfaces from one of the mold to its operative position thereon.
19. A multi-part mold as in claim 16 in which the ring en-gages the top portions of the mold parts and has an integral filler cup.
20. The process of claim 5 and including the steps of:
holding the parts in assembled relation; and heating the mold and ring to harden the material of the ring.
holding the parts in assembled relation; and heating the mold and ring to harden the material of the ring.
21. The process of claim 20 in which the step of forming the ring is accomplished by placing a form around the mold and filling the form with ceramic material in intimate contact with the mold parts.
22. The process of claim 20 in which the step of forming the ring is accomplished by successively dipping a part of the mold in a ceramic slurry to form a coating and drying the coating, and repeating the dipping and drying to produce a ring of the desired thickness.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US499224A US3927710A (en) | 1974-08-21 | 1974-08-21 | Joining of multi-section ceramic molds |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1064219A true CA1064219A (en) | 1979-10-16 |
Family
ID=23984356
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA231,420A Expired CA1064219A (en) | 1974-08-21 | 1975-07-11 | Joining of multi-section ceramic molds |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US3927710A (en) |
| JP (1) | JPS5159723A (en) |
| CA (1) | CA1064219A (en) |
| DE (1) | DE2536691A1 (en) |
| FR (1) | FR2282312A1 (en) |
| GB (1) | GB1523452A (en) |
| IL (1) | IL47953A (en) |
| IT (1) | IT1041959B (en) |
| SE (1) | SE7509055L (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4276922A (en) * | 1978-05-24 | 1981-07-07 | Trw Inc. | Plug mold assembly |
| GB9216726D0 (en) * | 1992-08-06 | 1992-09-23 | Labgas Res Lab Ltd | Ceramic member |
| JP2001505175A (en) * | 1996-06-05 | 2001-04-17 | ゼネラル エレクトリック カンパニイ | Method and apparatus for making directionally solidified castings |
| US6347660B1 (en) | 1998-12-01 | 2002-02-19 | Howmet Research Corporation | Multipiece core assembly for cast airfoil |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1248691A (en) * | 1917-02-24 | 1917-12-04 | Louis H Meister | Column-mold. |
| US2180422A (en) * | 1937-08-19 | 1939-11-21 | Harvey B Lindsay | Metal mold |
| US3515205A (en) * | 1968-03-20 | 1970-06-02 | United Aircraft Corp | Mold construction forming single crystal pieces |
| US3627015A (en) * | 1970-06-01 | 1971-12-14 | Hughes Aircraft Co | Cocoon casting of directionally solidified articles |
| US3690368A (en) * | 1970-08-14 | 1972-09-12 | United Aircraft Corp | Casting single crystal articles |
| JPS5152220Y2 (en) * | 1971-01-20 | 1976-12-14 | ||
| US3802482A (en) * | 1972-03-09 | 1974-04-09 | United Aircraft Corp | Process for making directionally solidified castings |
-
1974
- 1974-08-21 US US499224A patent/US3927710A/en not_active Expired - Lifetime
-
1975
- 1975-07-11 CA CA231,420A patent/CA1064219A/en not_active Expired
- 1975-08-13 SE SE7509055A patent/SE7509055L/en unknown
- 1975-08-18 DE DE19752536691 patent/DE2536691A1/en not_active Withdrawn
- 1975-08-19 FR FR7525605A patent/FR2282312A1/en not_active Withdrawn
- 1975-08-20 JP JP50101099A patent/JPS5159723A/en active Pending
- 1975-08-20 IL IL47953A patent/IL47953A/en unknown
- 1975-08-21 GB GB34754/75A patent/GB1523452A/en not_active Expired
- 1975-08-21 IT IT26476/75A patent/IT1041959B/en active
Also Published As
| Publication number | Publication date |
|---|---|
| SE7509055L (en) | 1976-02-23 |
| US3927710A (en) | 1975-12-23 |
| GB1523452A (en) | 1978-08-31 |
| FR2282312A1 (en) | 1976-03-19 |
| IL47953A (en) | 1980-11-30 |
| JPS5159723A (en) | 1976-05-25 |
| IT1041959B (en) | 1980-01-10 |
| DE2536691A1 (en) | 1976-03-04 |
| IL47953A0 (en) | 1975-11-25 |
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