PROTOTYPE SAND CASTING SYSTEM FOR PRODUCING A SAND CASTING PROTOTYPE THAT REPLICATES THE MATERIAL PROPERTIES OF A DIE-CAST PART

Abstract

A prototype sand casting system is provided for producing a sand casting prototype that replicates the material properties of a die-cast part. The prototype sand casting system includes a sand casting mold, a plurality of gates in fluid communication with the mold cavity, a gating system, a first furnace, and a second furnace. The plurality of gates are configured to direct a plurality of parallel casting alloys, including a first molten metal alloy and a second molten metal alloy, into the mold cavity to form the casting. The gating system is fluidly coupled to the plurality of gates. The first and second furnaces are fluidly coupled to the gating system. The first molten metal alloy and the second molten metal alloy are parallel casting alloys.

Description

INTRODUCTION

[0001] The present disclosure relates to the development of sand casting prototypes and, more particularly, to the development of sand casting prototypes having similar properties to a production die casting.

[0002] Die casting is a metal casting process characterized by the forcing of molten metal under high pressure into a mold cavity having a predetermined shape of a casting. Modern vehicles, particularly hybrid and electric vehicles, are evolving toward simpler vehicle body designs by die casting ultra-large, one-piece sheets and parts that serve as the supporting structure of the vehicle body. These ultra-large, one-piece castings are often referred to as mega- or giga-castings due to the enormous size of the die-casting machines used to produce them. Ultra-large castings allow vehicle bodies to be manufactured with less weight and complexity by replacing the large number of stamped sheets required to form the vehicle body with a single, one-piece casting.

[0003] Aluminum-silicon alloys are typically used for die casting vehicle body parts and ultra-large one-piece castings because they are lightweight, highly formable, can be produced in large quantities, and are high-strength. Traditionally, only one melt is used for each casting.

[0004] Developing a high-pressure die-casting (HPDC) prototype, especially for ultra-high-pressure or giga-casting parts, can be very expensive and time-consuming (often taking more than a year) when it comes to tool development. Prototype development for other metal casting processes, such as low-pressure die casting, counter-pressure die casting, and semi-permanent molding, can also suffer from the expensive and time-consuming development of metal molds. Due to the high costs and long lead times for metal molds, a sand casting process is often used for prototype development. However, due to the inherent differences between sand casting and metal casting processes (e.g., cooling rate, fill pattern, fill times, etc.), sand casting prototypes do not match the level or distribution of mechanical properties of metal mold production parts.

[0005] Although die-cast prototype development serves its purpose, there is a need for a new and improved process for developing die-cast prototypes or other metal mold production parts that minimizes time and cost. SUMMARY

[0006] According to one aspect of the present disclosure, a prototype sand casting system is provided for producing a sand casting prototype that replicates the material properties of a die-cast part. The prototype sand casting system includes a sand casting mold, a plurality of gates in fluid communication with the mold cavity, a gating system, a first furnace, and a second furnace. The sand casting mold includes a mold cavity having a predetermined shape of a casting. The plurality of gates are configured to direct a plurality of parallel casting alloys, including a first molten metal alloy and a second molten metal alloy, into the mold cavity to form the casting. The gating system is fluidly coupled to the plurality of gates, and the first molten metal alloy at least partially mixes with the second molten metal alloy in the gating system.The first furnace is fluidly coupled to the gating system, and the first furnace supplies the first molten metal alloy to the gating system. The second furnace is fluidly coupled to the gating system, and the second furnace supplies the second molten metal alloy to the gating system. The first molten metal alloy and the second molten metal alloy are parallel casting alloys. The first molten metal alloy and the second molten metal alloy are determined at least in part based on a virtual mold simulation to replicate the material properties of high-volume production die-cast (HPDC) parts, wherein the virtual mold simulation provides a prediction of the porosity and strain distribution in the sand casting prototype, and the predictions are used to determine the composition of the first molten metal alloy and the second molten metal alloy.

[0007] According to another aspect of the disclosure, the prototype sand casting system includes a gate system having a single gate that receives the first molten metal alloy and the second molten metal alloy. The first molten metal alloy and the second molten metal alloy mix in the single gate.

[0008] According to another aspect of the disclosure, the first molten metal alloy and the second molten metal alloy have different compositions.

[0009] According to another aspect of the disclosure, the prototype sand casting system includes a runner system having a first runner fluidly coupling the first furnace and the mold cavity and a second runner fluidly coupling the second furnace and the mold cavity.

[0010] According to another aspect of the disclosure, the prototype sand casting system includes a mold cavity in which the first molten metal alloy and the second molten metal alloy mix.

[0011] According to another aspect of the disclosure, the prototype sand casting system includes a third gate in fluid communication with the mold cavity and configured to direct a third molten metal alloy into the mold cavity to form the casting.

[0012] According to another aspect of the disclosure, the prototype sand casting system includes a third furnace that supplies a third molten metal alloy to the gating system.

[0013] According to another aspect of the disclosure, the prototype sand casting system includes a third molten metal alloy that is different from the first molten metal alloy and the second molten metal alloy.

[0014] According to another aspect of the disclosure, the prototype sand casting system includes at least one riser fluidly coupled to the mold cavity.

[0015] According to several aspects of the present disclosure, a prototype sand casting system is provided for producing a sand casting prototype that replicates the material properties of a die-cast part. The prototype sand casting system includes a sand casting mold, a first runner system, a second runner system, a first furnace, and a second furnace. The sand casting mold includes a mold cavity having a predetermined shape of a casting. The first runner system is in fluid communication with the mold cavity, and the first runner system directs a first molten metal alloy into the mold cavity to form the casting. The second runner system is in fluid communication with the mold cavity, and the second runner system directs a second molten metal alloy into the mold cavity to form the casting. The second molten metal alloy at least partially mixes with the first molten metal alloy in the mold cavity.The first furnace feeds the first molten metal alloy to the first gating system. The second furnace feeds the second molten metal alloy to the second gating system, and the first molten metal alloy and the second molten metal alloy flow in parallel into the mold cavity.

[0016] According to another aspect of the disclosure, the first molten metal alloy and the second molten metal alloy have different compositions.

[0017] According to another aspect of the disclosure, the first molten metal alloy and the second molten metal alloy have different compositions. The first molten metal alloy and the second molten metal alloy are determined at least in part based on a virtual mold simulation to replicate the material properties of high-volume production die-cast (HPDC) parts.

[0018] According to another aspect of the disclosure, the prototype sand casting system includes a third furnace that supplies a third molten metal alloy to a third gating system. The third gating system is fluidly coupled to the mold cavity and supplies the third molten metal alloy thereto.

[0019] According to another aspect of the disclosure, the third molten metal alloy is different from the first molten metal alloy and the second molten metal alloy.

[0020] According to another aspect of the disclosure, the prototype sand casting system includes at least one riser fluidly coupled to the mold cavity.

[0021] According to several aspects of the present disclosure, a method is provided for producing a sand casting prototype that replicates the material properties of a high-pressure die-cast part. The method includes feeding a first molten metal alloy from a first furnace to a gating system. The first molten metal alloy is determined at least in part based on a virtual die simulation to replicate the material properties of high-volume production die-cast (HPDC) parts. The method further includes feeding a second molten metal alloy from a second furnace to the gating system. The second molten metal alloy is determined at least in part based on a virtual die simulation to replicate the material properties of high-volume production die-cast (HPDC) parts.The method further comprises flowing the first molten metal alloy and the second molten metal alloy from the gating system into a sand casting mold having a mold cavity having a predetermined shape of a casting.

[0022] According to another aspect of the disclosure, the first molten metal alloy and the second molten metal alloy have different compositions.

[0023] According to another aspect of the disclosure, the method includes supplying a third molten metal alloy from a third furnace to the gating system. The third molten metal alloy is determined based at least in part on a virtual mold simulation to replicate the material properties of high-volume production die castings (HPDC parts).

[0024] According to another aspect of the disclosure, the third molten metal alloy is different from the first molten metal alloy and the second molten metal alloy.

[0025] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. Fig. 1 shows a schematic illustration of a simplified prototype sand casting system according to the present disclosure having a single gate gating system. Fig. 2 shows a schematic illustration of a simplified prototype sand casting system according to the present disclosure having a gating system with a first sprue and a second sprue. Fig. 3 shows the prototype sand casting system of Fig. 1 and Fig. 2 according to the present disclosure in a plan view. Fig. 4 shows the prototype sand casting system according to the present disclosure, which is Fig. 1 and Fig. 2 is shown, along the Fig. 3 illustrated lines 4-4 in a cross-sectional side view. Fig. 5 shows a flow chart illustrating a method for providing the sand casting prototype that has the material properties of a die-cast part using the prototype sand casting system according to the present disclosure, which is described in Fig. 1 and Fig. 2 is shown. DETAILED DESCRIPTION

[0027] The following description is merely exemplary and is not intended to limit the present disclosure, application, or uses. The illustrated embodiments are disclosed with reference to the drawings, wherein like numerals designate corresponding parts throughout the several drawings. The figures are not necessarily to scale, and some features may be larger or smaller to show details of particular features. The specific construction and functional details disclosed are not to be considered limiting, but rather as a representative basis for teaching one skilled in the art how to implement the disclosed concepts.

[0028] The system and method disclosed herein utilizes a virtual casting tool and multiple parallel casting alloys to match the mechanical properties and distribution of sand casting prototypes in a mold with a simulated production die-cast (HPDC) part. Typical mechanical property variations predicted in HPDC or other metal die castings are achieved by using these multiple parallel casting alloys in a sand casting prototype.

[0029] Fig. Figure 1 shows a schematic illustration of a simplified prototype sand casting system 10 according to one aspect of the present disclosure. The prototype sand casting system 10 is configured to provide a sand casting prototype with mechanical properties and distribution similar to or equivalent to the mechanical properties and distribution of an HPDC or other metal mold production part. The prototype sand casting system 10 includes a sand casting mold 12, at least one gate 14, a runner system 16, a first furnace 18, and a second furnace 20.

[0030] The Fig. The sand casting mold 12 shown in Figure 1 has an inner surface 22 defining a mold cavity 24. The mold cavity 24 is configured to receive molten metal to form a casting having a predetermined shape of the mold cavity 24. The inner surface 22 includes protrusions and cavities to define the mold cavity 24 having a predetermined shape and geometry for forming the desired contours and features of a casting, for example, for a vehicle (e.g., an engine block). Such protrusions and cavities may form walls and structural elements, such as bosses and ribs (not shown). The shape of the mold cavity 24 is a negative replica of the shape of the predetermined casting. The sand casting mold 12 may be additively manufactured (e.g., three-dimensional (3D) printed sand cores and molds) and may include a variety of sand compositions (e.g., silica) and sand bonding materials and processes.

[0031] As in Fig. 1, a riser 26 may be fluidly coupled to the mold cavity 24. The riser 26 is a reservoir coupled to the sand casting mold 12 to prevent voids in the mold due to shrinkage and to allow gas and vapor to escape from the mold cavity 24. As molten metal flows into the mold cavity 24, the molten metal enters the riser 26 once the mold cavity 24 is filled. Because the molten metal has a lower density than in the solid state, a void forms in the casting due to shrinkage during cooling. Molten metal is fed from the riser into the mold cavity 24 as the molten metal solidifies and shrinks. This creates a void in the riser 26 in place of the casting. The position and size of each riser 26 can be changed in the prototype sand casting system 10 to match the porosity expected from HPDC parts. Even if Fig. 1 illustrates three risers 26, it should be noted that fewer or more risers 26 can be arranged as part of the sand casting mold 12 and fluidly coupled to the mold cavity 24.

[0032] At least one molten metal or at least one molten alloy, e.g., a molten aluminum-silicon-based alloy, is introduced into the mold cavity 24. In determining the type of molten metal or alloy and the detailed composition, some considerations regarding the mechanical properties and distribution (e.g., ultimate tensile strength (UTS), yield strength (YS), elongation) and fatigue of each prototype may include the porosity-oxide volume fraction (greater porosity at greater distance from each gate), the volume fraction and size of the secondary phase particles, the spacing between the secondary dendrite arms (a sand casting cools more slowly than an HPDC casting, which is why the spacing between the secondary dendrite arms is typically greater in a sand casting than in an HPDC casting), and so on.Factors to consider when identifying molten metal alloys that affect local microstructure and defects may include alloy composition (when using multiple gates), melt treatment, runner / riser design, melt pouring temperature, a local 3D-printed core, local cooling, heat treatment design, multiple sand types used in the sand core, and / or sand bonding processes. The molten metal or alloy may include a variety of elements, such as aluminum (Al), silicon (Si), iron (Fe), copper (Cu), magnesium (Mg), manganese (Mn), zinc (Zn), strontium (Sr), and the like. The simulated molten metal alloy may be used for early product development, weldability, machining, mechanical property testing, and / or early product validation.

[0033] In one example, a first molten metal alloy 28 and a second molten metal alloy 30, which are different alloys and have a different metal alloy treatment, flow into the mold cavity 24 and at least partially mix therein. To replicate the HPDC casting, multiple parallel cast alloys are used. When HPDC prototypes are cast with a single melt, the melt at different locations in the mold may have different material properties (e.g., elongation) that are difficult to predict. For example, in HPDC casting, material property prediction is good near the gates, while it is less accurate further away from the gates, which is even more pronounced for gigacastings.The use of different molten metal alloys in a sand casting process is advantageous because each alloy behaves differently in different areas of the mold cavity 24 and can be used to predict molten metal alloys in an HPDC prototype mold. The first molten metal alloy 28 and the second molten metal alloy 30 can be arranged in different areas / zones of the mold cavity 24 to meet the mechanical property predictions of a metal mold (e.g., an HPDC mold). Using a sand casting prototype with multiple molten metal alloys thus leads to a better prediction of the consistent quality of the entire casting.

[0034] In one example, the first molten metal alloy 28 comprises an aluminum-silicon-based alloy, and the second molten metal alloy 30 is an aluminum-silicon-based alloy that is different from the first molten metal alloy 28. In some cases, and as in Fig. 1, a third molten metal alloy 32 may also flow from a third furnace 34 into the mold cavity 24 and at least partially mix with the first molten metal alloy 28 and the second molten metal alloy 30 within the mold cavity 24. In some cases, two of the first molten metal alloy 28, the second molten metal alloy 30, and the third molten metal alloy 32 may be the same alloy, while the remaining two are different alloys.

[0035] As in Fig. 1, the prototype sand casting system 10 includes at least one gate 14 (or internal gate). The gate 14 is in fluid communication with the mold cavity 24 and is a conduit configured to direct a molten metal alloy (e.g., the first molten metal alloy 28, the second molten metal alloy 30, the third molten metal alloy 32) into the mold cavity 24 to form the prototype sand casting. Each gate 14 is configured to ensure that the flow of the molten metal alloy is proportional to the volume of the mold cavity 24 for a given casting section and to ensure that the molten metal alloy completely fills the respective section of the mold cavity 24. Additionally, each gate 14 may allow for the mixing of multiple molten metal alloys (e.g.,the first molten metal alloy 28, the second molten metal alloy 30, the third molten metal alloy 32).

[0036] The location (e.g., a gate 14, the mold cavity 24, etc.) where the molten metal alloys are mixed can be determined using a virtual casting tool to optimize the properties of the sand casting material, such as porosity. Another mechanical property that can be predicted is the strain distribution throughout the sand casting prototype. Typically, the strain distribution and degradation increase proportionally with the distance from each gate 14. Therefore, if multiple gates are used and the location of each gate is optimized, less degradation of the entire sand casting prototype will occur. In the Fig. 1, the prototype sand casting system 10 includes a plurality of gates, including a first gate 14A, a second gate 14B, a third gate 14C, and a fourth gate 14D. In some aspects, the prototype sand casting system 10 may include additional gates (e.g., a fifth gate, a sixth gate, etc.) or fewer gates (e.g., three gates, two gates).

[0037] With further reference to Fig. 1, the gating system 16 consists of at least one gate 36 (e.g., a channel) fluidically coupled to the at least one gate 14. The gating system 16 enables the smooth flow of the molten metal to the at least one gate 14 and reduces the velocity of the molten metal, thus ensuring a uniform flow and preventing slag from entering the mold cavity 24. As shown in Fig. 1, the gating system 16 includes a single gate 36 fluidly coupled to the first gate 14A, the second gate 14B, the third gate 14C, and the fourth gate 14D. Using a single gate 36, the first molten metal alloy 28, the second molten metal alloy 30, and the third molten metal alloy 32 (if present) mix in the single gate 36, resulting in a smoother variation in the mechanical properties of the casting in the mold cavity 24.

[0038] With reference to Fig. 2 illustrates a prototype sand casting system 10 having a gating system 16 with a first sprue 38 and a second sprue 40. In this multi-sprue example, the prototype sand casting system 10 further includes a sand mold 12, a first furnace 18, and a second furnace 20. The first sprue 38 directly fluidically couples the first furnace 18 to the mold cavity 24 of the sand mold 12 such that the first molten metal alloy 28 does not contact the second sprue 40. The first sprue 38 allows the first molten metal alloy 28 to flow into the mold cavity 24. The second sprue 40 directly fluidically couples the second furnace 20 to the mold cavity 24 such that the second molten metal alloy 30 does not contact the first sprue 38. The second sprue 40 allows the second molten metal alloy 30 to flow directly into the mold cavity 24.It is possible that the first sprue 38 and the second sprue 40 do not have a separate gate as in the prototype sand casting system 10 shown in . Fig. 1, or may not include a gate at all. As the first molten metal alloy 28 and the second molten metal alloy 30 flow into the mold cavity 24, the first molten metal alloy 28 and the second molten metal alloy 30 at least partially mix while within the mold cavity 24 to replicate the material properties of an HPDC casting within the prototype sand casting system 10 and according to the predictions of the virtual casting tool.

[0039] With further reference to Fig. 1, the first furnace 18 is fluidly coupled to the gating system 16. The first furnace 18 is configured to melt the first molten metal alloy 28 and supply it to the gating system 16 and the mold cavity 24. The first furnace 18 may comprise, for example, an induction furnace, an arc furnace, a crucible furnace, and the like. Additionally, the first furnace 18 may be a low-pressure furnace and configured to supply the first molten metal alloy 28 to the gating system 16 with little or no pressure.

[0040] Additionally, Fig. 1 shows the second furnace 20, which is fluidly coupled to the gating system 16. The second furnace 20 is configured to supply the second molten metal alloy 30 to the gating system 16 and the mold cavity 24. The second furnace 20 may comprise, for example, an induction furnace, an arc furnace, a crucible furnace, and the like. Fig. 1 also illustrates the optional third furnace 34 fluidly coupled to the gating system 16 and supplying the third molten metal alloy 32 thereto. In some aspects, the prototype sand casting system 10 may include additional furnaces (e.g., a fourth furnace, a fifth furnace, etc.). Furthermore, the prototype sand casting system 10 may include additional components, e.g., a pouring device (not shown) for pouring each molten metal alloy from the respective furnaces.

[0041] Fig. 3 shows the prototype sand casting system 10, which in Fig. 1 and Fig. 2, in a plan view. The first molten metal alloy 28 flows into a first portion 42 of the mold cavity 24, as shown, and the second molten metal alloy 30 flows into a second portion 44 of the mold cavity 24, as shown. The first molten metal alloy 28 and the second molten metal alloy 30 at least partially mix within the mold cavity 24.

[0042] Fig. Figure 4 shows the prototype sand casting system 10 in a cross-sectional side view along lines 4-4 shown in Fig. 3. As in Fig. 3, the first molten metal alloy 28 flows through a first gate 14A into the first part 42 of the mold cavity 24 and the second molten metal alloy 30 flows through a second gate 14B into the second part 44 of the mold cavity 24. The view in Fig. 4 shows the mixing of the first molten metal alloy 28 and the second molten metal alloy 30 near a central location 46 between the first gate 14A and the second gate 14B. In other cases, the first molten metal alloy 28 and the second molten metal alloy 30 (and other alloys, if present) also mix throughout the mold cavity 24.

[0043] Fig. Figure 5 shows a flow chart illustrating a method 100 for providing the sand casting prototype that has the material properties of a die-cast part using the prototype sand casting system 10 shown in Fig. 1 and Fig. 2 is copied.

[0044] Beginning at block 102, the method 100 includes supplying the first molten metal alloy 28 from the first furnace 18 to a gating system 16. Providing the first molten metal alloy 28 may include determining the composition of the first molten metal alloy 28. The composition of the first molten metal alloy 28 is determined based at least in part on a virtual mold. The virtual mold may include a software simulation configured to design and adjust multi-scale defects and microstructure in the sand casting prototype. The virtual mold determines the composition of the first molten metal alloy 28 to replicate or replicate the material properties of high-volume production die-cast (HPDC) parts.In one example, the virtual casting tool determines a castable product geometry, provides a simulation of the sand casting process, provides a prediction of the microstructure and porosity of a sand cast prototype, and provides a prediction of the local properties of a sand cast prototype part. The simulation and the resulting predictions are then used to determine and provide the composition of the first molten metal alloy 28. The method 100 then proceeds to block 104.

[0045] Block 104 includes supplying the second molten metal alloy 30 from the second furnace 20 to the gating system 16. The composition of the second molten metal alloy 30 is determined based at least in part on the virtual casting tool. Similar to the first molten metal alloy 28, the virtual casting tool determines the composition of the second molten metal alloy 30 to replicate the material properties of high-volume production die castings (HPDC) parts from the sand casting simulation predictions. The method 100 may then proceed to block 106.

[0046] Block 106 includes an optional step of supplying a third molten metal alloy 32 from a third furnace 34 to the gating system 16. The composition of the third molten metal alloy 32 (if present) is determined based at least in part on the virtual mold. The virtual mold determines the composition of the third molten metal alloy 32 to replicate the material properties of high-volume production die-cast (HPDC) parts. The method 100 then proceeds to block 108.

[0047] Block 108 includes flowing the first molten metal alloy 28 and the second molten metal alloy 30 from the gating system 16 into the sand casting mold 12 and the mold cavity 24. Flowing the first molten metal alloy 28 and the second molten metal alloy 30 includes pouring each molten metal alloy from the first furnace 18, the second furnace 20, and / or the third furnace 34. The virtual tool prediction and prototype casting steps (e.g., block 102, block 104, block 106, and / or block 108) may be repeated until the mechanical properties of the sand casting prototype are similar to or equivalent to the predicted mechanical properties of the HPDC product. The method 100 is then complete.

[0048] The prototype sand casting system 10 and method 100 for producing a sand casting prototype of the present disclosure offer several advantages. Since developing a high pressure die cast (HPDC) prototype part can be expensive and time-consuming, the prototype sand casting system 10 is advantageously designed to replicate an HPDC process rather than being optimized for the best sand casting material properties. Using the sand casting process for developing the HPDC prototype reduces the time and cost required because the time and cost of sand casting are lower.

Claims

[1] Prototype sand casting system (10) for producing a sand casting prototype that replicates the material properties of a die-cast part, comprising: a sand casting mold (12) comprising a mold cavity (24) having a predetermined shape of a casting, a plurality of gates (14) in fluid communication with the mold cavity (24), the plurality of gates (14) being configured to direct parallel casting alloys comprising a first molten metal alloy (28) and a second molten metal alloy (30) into the mold cavity (24) to form the casting, a gating system (16) fluidly coupled to the plurality of gates (14), wherein the first molten metal alloy (28) in the gating system (16) is at least partially mixed with the second molten metal alloy (30), a first furnace (18) fluidly coupled to the gating system (16), wherein the first furnace (18) supplies the first molten metal alloy (28) to the gating system (16), and a second furnace (20) fluidly coupled to the gating system (16), wherein the second furnace (20) supplies the second molten metal alloy (30) to the gating system (16), and wherein the first molten metal alloy (28) and the second molten metal alloy (30) are parallel casting alloys, wherein the first molten metal alloy (28) and the second molten metal alloy (30) are determined at least in part based on a virtual casting tool simulation to replicate the material properties of high-volume production die-cast (HPDC) parts, wherein the virtual casting tool simulation provides a prediction of the porosity and strain distribution in the sand casting prototype, and the predictions are used to determine the composition of the first molten metal alloy (28) and the second molten metal alloy (30). [2] The prototype sand casting system (10) of claim 1, wherein the runner system (16) is a single runner (36) receiving the first molten metal alloy (28) and the second molten metal alloy (30), and wherein the first molten metal alloy (28) and the second molten metal alloy (30) mix in the single runner (36). [3] The prototype sand casting system (10) of claim 1, wherein the first molten metal alloy (28) and the second molten metal alloy (30) have different compositions. [4] The prototype sand casting system (10) of claim 1, wherein the gating system (16) comprises a first gating system (38) fluidly coupling the first furnace (18) and the mold cavity (24) and a second gating system (40) fluidly coupling the second furnace (20) and the mold cavity (24). [5] The prototype sand casting system (10) of claim 3, wherein the first molten metal alloy (28) and the second molten metal alloy (30) mix in the mold cavity (24). [6] Prototype sand casting system (10) according to claim 1, further comprising: a third gate (14) in fluid communication with the mold cavity (24) adapted to direct a third molten metal alloy (32) into the mold cavity (24) to form the casting. [7] Prototype sand casting system (10) according to claim 1, further comprising: a third furnace (34) which supplies a third molten metal alloy (32) to the gating system (16). [8] The prototype sand casting system (10) of claim 7, wherein the third molten metal alloy (32) is different from the first molten metal alloy (28) and the second molten metal alloy (30). [9] Prototype sand casting system (10) according to claim 1, further comprising: at least one riser (26) which is fluidically coupled to the mold cavity (24).

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