US20020124987A1

US20020124987A1 - Casting apparatus with mold handling/positioning fixture

Info

Publication number: US20020124987A1
Application number: US09/803,409
Authority: US
Inventors: Mark Soderstrom; Christophe Charpentier
Original assignee: Howmet Research Corp
Current assignee: Howmet Corp
Priority date: 2001-03-09
Filing date: 2001-03-09
Publication date: 2002-09-12
Also published as: DE10210259A1; GB0205154D0; FR2821775A1; GB2372953A

Abstract

Investment shell mold has a locating fixture thereon by which the shell mold can be handled and moved between a mold heating chamber and a casting chamber by a mold manipulator. The mold manipulator positions the preheated mold in the casting chamber to cooperatively engage a locator fixture disposed in the casting chamber. The locator fixture orients the preheated mold in predetermined position relative to a melt-delivery vessel in the casting chamber so as to receive melt therefrom.

Description

FIELD OF THE INVENTION

The present invention relates to casting apparatus and shell molds for casting of molten metallic materials.

BACKGROUND OF THE INVENTION

In the conduct of investment casting operations, a ceramic investment shell mold is formed by the well known lost wax process where a fugitive (e.g. wax) pattern of the article to be cast is repeatedly dipped in a slurry of fine ceramic powder, drained of excess slurry, stuccoed with coarse ceramic particles, and air dried until an investment shell mold is built up to a desired shell mold wall thickness on the pattern. The pattern then is removed from the shell mold by thermal or chemical treatment, leaving a green shell mold which is then fired in a furnace to develop mold strength for casting of molten metal or alloy therein. To this end, the fired shell mold is preheated in a mold furnace or chamber and then positioned in a casting furnace or chamber where the molten metal or alloy is introduced into the shell mold. The shell mold typically is positioned in a casting furnace or chamber with a shell mold pour cup located below a melt-holding crucible from which the molten metal or alloy is bottom poured or lip poured by tilting the crucible into the underlying shell mold. U.S. Pat. Nos. 5, 309,976; 5,592,984; 5,931,214; and 6,019,158 describe investment shell mold casting apparatus where a preheated ceramic investment shell mold is positioned relative to a crucible to receive molten metal or alloy therefrom.

In one particular casting apparatus, a melting chamber is separated or isolated from an underlying mold-receiving chamber by a suitable isolation valve, such as sliding gate valve, that allows a vacuum to be maintained in the melting chamber. An individual charge of metal, such as an individual ingot, is melted under vacuum (subambient pressure) in the crucible in the melting chamber above the mold-receiving chamber. When the charge is determined to be at an appropriate casting temperature, an operator calls for a preheated mold to be removed from the mold heating furnace and positioned in the vacuum chamber for casting. For example, a mold handler manually removes a preheated mold from the mold heating furnace and manually positions the preheated mold on a mold pan beneath the melting chamber sealed by the closed isolation valve. After the isolation valve to the melting chamber is opened, the preheated mold is raised by an elevator under the mold pan to a preselected height in the melting chamber below the crucible. The crucible then is pivoted in a manner to pour the molten metal as a free molten metal stream into a frusto-conical pour cup of the preheated mold positioned therebelow in the melting chamber. The pour cup has a simple frusto-conical receptacle to receive the stream from the crucible and direct it into the mold to fill same. After filling of the mold with molten metal, the mold is lowered on the mold pan by the elevator into the mold-receiving chamber, and the isolation valve is closed. The melt filled mold can remain in the mold-receiving chamber or removed therefrom for solidification of the molten metal therein. This cycle is repeated to cast a plurality of preheated molds one a time over the casting campaign.

In such casting campaigns, the manual placement or positioning of the preheated mold on the mold pan in the vacuum chamber results in variations in mold alignment relative to the crucible in the melting chamber. This alignment variation from one mold to the next typically is greatest at the beginning of a casting campaign and also when there is a change in the mold used and/or product (casting) being produced. As molds are cast in a campaign, adjustments can be made by the mold handler until a near optimum preheated mold position is consistently achieved during the remainder of the campaign. However, as “just in time” manufacturing procedures are adopted, more numerous, shorter run casting campaigns are being used such that the problem of misalignment of molds relative to the melting crucible becomes more troublesome.

The alignment variation from one mold to the next during a casting campaign adversely affects the alignment of the molten metal stream poured from the crucible into the mold pour cup of respective molds. For example, such misalignment produces melt splashing because the pour cup backs up with molten metal due to the misalignment. Short pours and lower mold gating efficiency are observed as a result. Moreover, such misalignment produces molten metal swirling in the pour cup that increases dwell time of the melt in the relatively cooler mold pour cup, producing a loss of thermal energy and resultant cold shuts and chill grain defects in the casting, and that decreases axial momentum of the molten metal stream, producing variability in mold filling time and decreased laminar metal flow and increased metal turbulence within the mold. Turbulence within the mold can cause the flowing molten metal to form eddies, reducing metal pressure and velocity, and result in misrun in thin sections of the mold as well as oxide formation that leads to dross formation. Variations in the mold filling patterns from one mold to the next can increase porosity in castings produced during a particular casting campaign.

Copending application Ser. No. 09/255,187 describes a shell mold pour cup wall that includes a plurality of anti-swirl ribs circumferentially spaced apart about the periphery of the pour cup in a manner to reduce swirling of molten metal poured in the pour cup as a result of misalignment between the mold pour cup and pouring vessel.

There is a need to improve control over handling and alignment of an investment shell mold relative to a melting crucible, or other melt-delivery vessel, disposed in a casting furnace.

An object of the present invention is to satisfy this need.

SUMMARY OF THE INVENTION

The present invention provides in one illustrative embodiment an investment shell mold having a mold locating fixture thereon by which the shell mold can be handled and moved between a mold heating chamber and a casting chamber by a mold manipulator. The mold manipulator positions the preheated mold in the casting chamber to cooperatively engage a locator fixture disposed in the casting chamber. The chamber locator fixture orients the preheated mold in predetermined position relative to a melt-delivery device, such as a melt delivery vessel, in the casting chamber so as to receive melt therefrom.

The mold locating fixture can be formed integrally with the shell mold and be adapted to be engaged by a robotic or manual mold manipulator, such as for example a mold pick-up tool. The casting chamber can comprise a casting furnace with the furnace having a locator fixture therein on which the mold locating fixture is positioned to orient the shell mold relative to a melting crucible in the casting furnace so as to position the mold in predetermined orientation for receiving melt from the crucible. Alternately, a movable elevator ram in the casting chamber can include a locator fixture to this same end.

The above and other objects and advantages of the present invention will become more readily apparent from the following drawings taken in conjunction with the following detailed description.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a shell mold in a mold heating furnace, the shell mold having a mold locating fixture pursuant to an embodiment of the invention for engagement by a mold pick-up tool. [0012]
FIG. 2 is a schematic perspective view of the shell mold positioned on a locator fixture in a casting chamber to locate the mold relative to a melt-delivery vessel communicated to the casting chamber. [0013]
FIG. 3 is a schematic plan view of the mold locating fixture members disposed on the locator fixture in the casting chamber. [0014]
FIG. 4 is an end elevation of a mold locating fixture member formed on the shell mold pursuant to an embodiment of the invention. [0015]
FIG. 5 is a schematic perspective view of a pattern assembly used to make the shell mold by the lost wax process. [0016]
FIG. 6 is a schematic perspective view of an elevator ram in a casting chamber having a locator fixture to locate the mold relative to a melt-delivery vessel communicated to the casting chamber. [0017]
FIG. 7 is an exploded schematic perspective view of a shell mold on a locator fixture on an elevator ram in a casting chamber to locate the mold relative to a melt-delivery vessel communicated to the casting chamber. [0018]
FIG. 8 is a schematic plan view of the preheated mold on the locator fixture on the elevator ram. [0019]
FIG. 9 is a schematic perspective view of a shell mold of another embodiment of the invention. [0020]
FIG. 10 is an exploded schematic perspective view of a shell mold for positioning on a locator fixture pursuant to another embodiment of the invention on an elevator ram in a casting chamber to locate the mold relative to a melt-delivery vessel communicated to the casting chamber.[0021]

DESCRIPTION OF THE INVENTION

FIGS. [0022] 1 to 4 illustrate schematically a casting apparatus for casting molten metal or alloy (hereafter molten metallic material) into a ceramic investment shell mold 10 in a casting furnace chamber 70. The shell mold 10 is shown comprising an integral frusto-conical pour cup 10 a connected to a main mold body 10 b having one or more internal mold cavities 10 c (one shown) therein. A sprue 10 d with internal passage 10 e connects the pour cup 10 a and the mold cavity 10 c so that molten metallic material in the pour cup 10 a flows into the mold cavity 10 b. The mold cavity 10 c has the shape of an article to be cast. For example, in FIG. 1, the mold cavity 10 c may have a shape of a turbine wheel.
Pursuant to an embodiment of the present invention, the [0023] shell mold 10 also includes a mold locating fixture 12 comprising first and second elongated rod-shaped locating fixture members 12 a formed integrally on the exterior of the mold pour cup 10 a. Each rod-shaped fixture member 12 a preferably has a flat lowermost surface 12 b, FIG. 4. The remaining peripheral surface 12 c of each fixture member 12 a can have an arcuate or any other shape such as a polygonal shape or round shape. The rod-shaped fixture members 12 a are of equal length and are arranged on opposite diametral sides of the pour cup 10 a in a common horizontal plane and substantially parallel to one another in the common plane. The lowermost flat surfaces 12 b of the fixture members 12 a collectively define a reference locating horizontal plane or platform by which the shell mold 10 can be picked-up, moved and positioned by a mold pick-up or other manipulator tool 50.
The [0024] mold 10 is formed using a wax or other fugitive pattern assembly 20 shown in FIG. 5 having a fugitive (e.g. wax) sections 20 a, 20 b, 20 d and rods 22 corresponding to the pour cup 10 a, main mold body 10 b, sprue 10 d and mold locating fixture members 12 a. The wax rods 22 comprise first and second solid fugitive (e.g. wax) rods that are wax welded, formed integrally, or otherwise attached, on the exterior of opposite diametral sides of pour cup section 20 a of the pattern assembly to form the fixture members 12 a. Wax rods 22 can be injection molded integrally with the pour cup of the pattern assembly 20, or preformed and attached by wax welding to the wax pattern assembly 20. Alternately, the wax rods 22 can be attached to the pour cup 10 a after one or more ceramic layers are applied on the pattern assembly 20. Alternately, the rods 22 can comprise preformed ceramic or other refractory material rods adhered to the wax pour cup or to one or more ceramic layers applied to wax pour cup of the pattern assembly 20. The rods 22 are formed or attached on opposite diametral sides of the pour cup section 20 a in a common horizontal plane and substantially parallel to one another in the common plane to form the fixture members 12 a when the pattern assembly is invested in the shell mold 10. Each rod 22 will have a lowermost flat surface 22 b and arcuate (or other shape) surface 22 c complementary to surfaces 12 b, 12 c of the fixture members 12 a.
The [0025] shell mold 10 typically comprises a ceramic investment shell mold made by the well known lost wax process where the fugitive (e.g. wax) pattern assembly 20 is repeatedly dipped in a slurry of fine ceramic powder, drained of excess slurry, stuccoed with relatively coarse ceramic particles, and air dried until an investment shell mold is built up to a desired shell mold wall thickness on the pattern. The fugitive pattern assembly then is removed from the shell mold by thermal or chemical treatment, leaving the green shell mold 10 which is then fired in a furnace to develop mold strength for casting of molten metal or alloy therein. The lost wax process for making shell molds is described in U.S. Pat. Nos. 5,335,717 and 5,297,615, the teachings of which are incorporated herein by reference. The ceramic materials used in the fabrication of the ceramic slurry and coarse ceramic particles will be selected in dependence upon the particular metallic material to be cast into the shell mold and form no part of the present invention.
After the pattern assembly is removed, the [0026] green shell mold 10 is fired or sintered in a furnace (not shown) at an elevated firing temperature to impart sufficient mold strength for casting of molten metallic material in the shell mold.
In preparation for casting, the fired [0027] shell mold 10 is preheated in a mold heating furnace chamber 60, FIG. 1, and then positioned in a casting furnace chamber 70, FIG. 2, where the molten metal or alloy is introduced into the shell mold 10 from a melt-holding vessel 80, such a melting crucible 82. The mold heating furnace chamber 60 is shown separate from the casting furnace chamber 70, FIG. 1, although the invention is not so limited since the chambers 60, 70 can be communicated to one another. The preheated shell mold 10 then can be moved from the mold heating furnace chamber 60 into the casting furnace chamber 70.
Pursuant to the present invention, the [0028] shell mold 10 is moved by means of mold pick-up tool 50 shown having a bifurcated fork-shaped end 50 a adapted to be positioned about the mold sprue 10 d and under and supportively engaging the surfaces 12 b of fixture members 12 a to lift and support the preheated shell mold 10 during transport into and out of the mold heating chamber 60 and then from the mold heating chamber 60 to the casting chamber 70. The tool 50 includes an elongated tool arm 50 b that can be manipulated by a robotic device (not shown) or manually by a human worker gripping and manipulating the tool arm 50 b. The tool 50 can be made of steel or other suitable material.
The [0029] shell mold 10 can be placed on a heat resistant or other support tray T residing in the mold heating furnace chamber 60 by the tool 50, which then is withdrawn from the furnace chamber 60 until the shell mold 10 is ready to be picked up and moved to the casting chamber 70. The furnace chamber 60 includes a conventional sealable access door (not shown) through which the shell mold 10 and tool 50 can moved into and out of the furnace chamber.
After the [0030] shell mold 10 is preheated in the mold heating furnace chamber 60, it is removed therefrom via the furnace door using tool 50 and transported using tool 50 to the casting chamber 70, FIG. 2, having a locator fixture 90 adapted to cooperatively engage, support and locate the fixture members 12 a of the shell mold 10 to orient it properly with respect to the melt-holding vessel 80 communicated to the casting chamber. The melt-delivery vessel 80 can comprise a melting crucible 82 tiltable about trunnions 82 a (one shown) on opposite sides of the crucible to pour molten metallic material M therein over the crucible lip 82 b and into the pour cup 10 a of the shell mold 10.
The [0031] locator fixture 90 comprises spaced apart, parallel side rails 92 each having a horizontal surface 92 a and vertical surface 92 b. The surfaces 92 a are coplanar to define a reference horizontal plane in a height direction H relative to the vessel 80. The surfaces 92 b are parallel to define respective reference vertical planes spaced apart in a lateral direction L normal to direction H. The lateral (horizontal) distance between upstanding surfaces 92 b is controlled to provide the desired lateral orientation of the shell mold 10 with respect to the vessel 80. Back or rear vertical surfaces 92 c are provided on rails 92 and located in a common vertical plane perpendicular to the plane containing surfaces 92 a and the plane containing surfaces 92 b to control and limit movement of the mold in the depth direction D in the chamber 70.
In particular, the lowermost [0032] flat surfaces 12 b of the mold locating fixture members 12 a are positioned by tool 50 on the coplanar horizontal surfaces 92 a between the upstanding surfaces 92 b with the outermost lateral ends 12 e of the fixture members 12 proximate to or abutting surfaces 92 b and the rearmost member 12 a proximate to or abutting surfaces 92 c. The tool 50 lowers the shell mold 10 on the locator fixture 90. The shell mold 10 thereby is positioned at a proper vertical height in the direction H and orientations in the directions L and D relative to the vessel 80 to provide accurate control over the shell mold position relative to the vessel 80.
The locator rails [0033] 92 can be mounted in the casting chamber 70 on the sidewalls 70 a thereof using suitable steel or other connector members 97 fastened between the rails and sidewalls, FIG. 2.
Alternately, referring to FIG. 6, the locator rails [0034] 92 can be connected to a back rail 94 that is fastened and supported on an upstanding rail support member 93 fastened on a mold pan 95 that is disposed and fastened on the top of movable elevator ram R, FIG. 6. The back rail 94 is disposed between the rails 92 and forms the vertical locating surfaces 92 c in this embodiment to control mold location in the direction D. Rail surfaces 92 a, 92 b are cooperably associated with rail 94. Rail surfaces 92 b control mold location in the L direction. The elevator ram R is movable up and down in chamber 70 to move the mold 10 on locator rails 92 toward and away from the vessel 80 to control mold location in the H direction. The casting chamber 70 includes a conventional access door (not shown) that is opened to permit placement of the shell mold 10 on the locator fixture 90.
After the [0035] shell mold 10 is positioned on the locating fixture 90 in the casting chamber 70, the tool 50 is disengaged and withdrawn from the fixtures members 12 a, leaving the shell mold 10 resting on and located with respect to the vessel 80 in the chamber 70. The chamber access door then can be closed and sealed to permit melting of the metallic material under vacuum or inert gas atmosphere in the chamber 70 and subsequent pouring of the molten metallic material from the vessel 80 into the shell mold 10 properly positioned to this end with respect to the vessel 80 by the locating fixture 90.
The casting [0036] furnace chamber 70 may include an optional isolation valve 100, such as sliding gate valve, that when closed will permit the metallic material M to be melted under vacuum (subambient pressure) or inert gas atmosphere in a melting chamber 75, while the preheated shell mold 10 is placed in the casting chamber 70 on the locating fixture 90 below the isolation valve 100. The access door then is closed and sealed to permit the casting chamber below the isolation valve 100 to be evacuated to subambient pressure or to receive inert gas atmosphere before the isolation valve 100 is opened and the molten metallic material poured from the vessel 80 into the shell mold 10.
If the elevator ram R is present in casting [0037] furnace chamber 70, FIG. 6, it is movable upwardly in chamber 70 to move the shell mold 10 to a casting position proximate and below the vessel 80. After the shell mold is cast with molten metal or alloy from vessel 80, the ram R is lowered to lower the cast shell mold 10 containing the metallic material M to a lower position in chamber 70 for removal from the casting furnace chamber 70.
The [0038] cast shell mold 10 containing the metallic material M can be removed from the casting furnace chamber 70 at any suitable time before or after complete solidification of the metallic material therein. A vacuum or inert gas atmosphere in the casting furnace chamber 70 can be replaced with ambient air so that the access door can be opened and the tool 50 moved into chamber 70 and engaged under mold fixture surfaces 12 b to lift the cast shell mold 10 off of the locator fixture 90 and moved out of the chamber 70 for further processing.
The present invention is advantageous to insure consistent and accurate positioning of [0039] successive shell molds 10 relative to the vessel 80 in the casting furnace chamber 70. Improved alignment from one mold to the next during a casting campaign will reduce melt splashing and short pours as well as improve mold gating efficiency. Moreover, swirling of molten metallic material in the pour cup will be reduced to decrease dwell time of the melt in the relatively cooler mold pour cup so as to reduce loss of thermal energy, resultant cold shuts and chill grain defects in the casting. Reduction in such swirling in the pour cup can reduce variability in mold filling times and laminar metal flow and an decrease metal turbulence within the mold.
Although the [0040] mold locating fixture 12 and locator fixture 90 have been described with respect to first and second rod-shaped mold fixture members 12 a for positioning on locating rails 92, the invention is not so limited and can be practiced using other configurations for the mold fixture 12 and locator fixture 90. For example, referring to FIGS. 7 and 8 where like features are represented by like reference numerals primed, the mold locating fixture 12′ is illustrated comprising a D-shaped locating flange 13′ formed integrally on the mold pour cup 10 a′. The locating flange 13′ includes a laterally extending planar platform locating portion 13 a′ and an annular lip 13 b′ about the pour cup 10 a′. The tool 50′ can be inserted under the lip 13 b′ to lift and move the mold 10′ from a mold heating furnace (not shown) similar to that shown in FIG. 1 to a casting furnace chamber 70′ similar to that shown in FIG. 2. The locator fixture 90′ includes locator side rails 92′ and back rail 94′ provided on a rail support member 93′ fastened on a mold pan 95′ that is disposed and fastened on the top of movable elevator ram R′, FIG. 7. The tool 50′ positions the preheated shell mold 10′ in chamber 70′ on the rails 92′ in a manner that flange locating portion 13 a′ is received on one rail 92′ (left hand rail in FIG. 8) and the lip 13 b′ is received on the other rail 92′ (right hand rail in FIG. 8) with the flange locating portion 13 a′ received in the corner C′ defined by perpendicularly oriented side rail 92′ and back rail 94′ as shown. Casting of the thusly located mold 10′ is conducted as described hereabove.
In another embodiment of the invention illustrated in FIG. 9 where like features are represented by like reference numerals double primed, the locating [0041] fixture 12″ of the shell mold 10″ can comprise a flat planar plate-like member 15″ provided on pour cup 10 a″. The tool 50″ can be inserted under the member 15″ to lift and move the mold 10″ from a mold heating furnace (not shown) similar to that shown in FIG. 1 to a casting furnace chamber (not shown) similar to that shown in FIG. 2.
The locator fixture in [0042] chamber 70 is not limited to the rails 92, 94 (92′, 94′) discussed hereabove and may comprise other fixture configurations to receive and locate the mold locating fixture. For example, referring to FIG. 10 where like features are represented by like reference numerals triple primed, the locator fixture 90′″ can comprise a receptacle or box 17′″ disposed and fastened on elevator ram R′″ to locate the shell mold 10′″ in the chamber 70′″. For example, a box 17′″ with an open top, locator surfaces 17 a′″, 17 b′″ and 17 c′″, and closed bottom 17 d′″ is shown positioned on ram R′″ in chamber 70″″. The surfaces 17 a′″, 17 b′″, and 17 c′″ correspond in function with surfaces 92 a′, 92 b′, 92 c′ of FIG. 8. The surfaces 17 a′″ receive thereon the locating flange 13 a″″ and the lip 13 b″″ to cooperate with the surfaces 17 b′″ and 17 c′″ to properly position the shell mold with respect to the melt-holding vessel. The front and rear walls 17 s′″ can have a configuration necessary to allow the tool 50′″ to lower the mold 10′″ onto the locator flanges 17 a′″. Other box or receptacle configurations are possible as well.
Moreover, although a [0043] mold heating chamber 60 separate from casting chamber 70 have been described, the mold heating chamber can be communicated to the casting chamber. For example, in FIG. 2, the casting chamber 70 can communicate directly to the casting chamber 70 by an access door, passage or opening therebetween. Further, in FIG. 2, casting chamber 70 can include conventional heating elements to preheat the shell mold 10 therein to a selected mold casting temperature prior to pouring of molten metal or metal alloy from the crucible. In this embodiment, the casting chamber 70 also comprises the mold heating chamber.
Although the invention has been described above with respect to certain embodiments, those skilled in the art will appreciate that modifications and the like can be made therein without departing from the scope of the invention as set forth in the appended claims. [0044]

Claims

We claim

1. Casting apparatus, comprising a mold having a mold locating fixture thereon, a casting chamber including a melt-delivery device from which the mold receives a melt, a locator fixture disposed in the casting chamber, and a mold manipulator for positioning said mold in said casting chamber with said mold locating fixture cooperatively engaged with the locator fixture in the casting chamber to locate said mold relative to said melt-delivery device.

2. The apparatus of claim 1 wherein the mold locating fixture is integral to the shell mold.

3. The apparatus of claim 2 wherein the mold locating fixture is integral to a pour cup of the mold.

4. The apparatus of claim 1 wherein the mold fixture comprises first and second coplanar member on opposite sides of the pour cup.

5. The apparatus of claim 1 wherein the mold fixture comprises a planar member proximate the pour cup.

6. The apparatus of claim 1 wherein said melt-delivery device is a crucible communicated to the casting chamber.

7. The apparatus of claim 5 wherein the crucible is a tiltable to pour melt therefrom into the mold.

8. The apparatus of claim 1 wherein the locator fixture comprises first and second parallel rails with each rail having a horizontal surface and vertical surface.

9. The apparatus of claim 8 wherein the horizontal surfaces are coplanar to define a reference horizontal plane in a height direction.

10. The apparatus of claim 8 wherein the vertical surfaces are parallel to define reference vertical planes spaced apart in a lateral direction normal to the horizontal plane.

11. The apparatus of claim 8 wherein the first and second rails are cooperably associated with a vertical surface that controls location of the mold in a direction perpendicular to the height direction and lateral direction.

12. The apparatus of claim 11 wherein the vertical surface is formed by a third rail disposed between the first and second rails.

13. The apparatus of claim 11 wherein said surfaces position the shell mold at a vertical height and first and second lateral orientations relative to a melt-delivery vessel.

14. The apparatus of claim 1 wherein the mold manipulator comprises a mold pick-up tool to engage said mold locating fixture.

15. A method of casting molten metallic material, comprising providing a mold to have a mold locating fixture thereon and positioning the mold in a casting chamber with said mold locating fixture in cooperative engagement with a locator fixture disposed in said casting chamber so as to orient the mold to receive molten metallic material.

16. The method of claim 15 including providing the mold locating fixture integrally on the mold.

17. The method of claim 16 wherein the mold locating fixture is formed integrally on a pour cup of the mold.

18. The method of claim 17 wherein the mold fixture comprises first and second coplanar members on opposite sides of the pour cup.

19. The method of claim 15 wherein the locator fixture comprises a first and second parallel rails with each rail having a horizontal surface and vertical surface.

20. The method of claim 19 wherein the locator fixture includes a vertical surface that controls location of the mold in a direction perpendicular to the horizontal surfaces and vertical surfaces.

21. The method of claim 15 including disposing a melt-delivery vessel to communicate to the casting chamber.

22. The method of claim 21 wherein the locator fixture positions the mold in predetermined position relative to the melt-delivery vessel.

23. The method of claim 15 including lifting the preheated mold by the mold manipulator.

24. The method of claim 23 including lowering the preheated mold onto the locator fixture in the casting chamber.

25. Method of casting molten metallic material, comprising:

preheating a mold in a mold heating chamber,

engaging a mold manipulator with a mold locating fixture disposed on the mold,

moving the preheated mold using the mold manipulator from the mold heating chamber to a casting chamber having a melt-delivery vessel,

positioning the preheated mold in the casting chamber with the mold locating fixture cooperatively engaged with a locator fixture in the casting furnace so as to position the preheated mold at a vertical height and lateral orientation relative to the melt-delivery vessel, and

transferring molten metallic material from the melt-delivery device into the preheated mold.