A composite runner and casting method for a light-weight high-toughness diesel engine cylinder head
By designing a composite gating system and using electromagnetic stirring technology, the problem of unstable filling in the casting of medium-entropy eutectic alloy cylinder heads was solved, and the preparation of high-performance lightweight diesel engine cylinder heads was realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN TECH UNIV
- Filing Date
- 2026-04-17
- Publication Date
- 2026-06-09
AI Technical Summary
Existing gating designs are ill-suited to the flow characteristics and solidification features of high-melting-point medium-entropy eutectic alloys, resulting in numerous casting defects and unstable performance in diesel engine cylinder heads.
A composite gating system is adopted, including a straight gating system, a horizontal gating system, a stepped ingate system, and a top riser. Combined with an inclined feeding channel, electromagnetic stirring, and strict control of the filling time, stable filling and sequential solidification are achieved.
It significantly reduces the shrinkage porosity defect rate, improves the strength and toughness of castings, achieves lightweighting, and extends mechanical and thermal fatigue life.
Smart Images
Figure CN122164859A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of diesel engine key component manufacturing, specifically relating to a composite gating system and casting method for a lightweight, high-strength, and tough diesel engine cylinder head. Background Technology
[0002] The cylinder head is one of the core components of a diesel engine, integrating key structures such as the intake manifold, exhaust manifold, and combustion chamber. During operation, it must withstand high-temperature impacts exceeding 1000°C, enormous mechanical loads, and high-frequency thermal cycling. Therefore, stringent requirements are placed on the strength, toughness, thermal conductivity, and lightweight properties of the materials used. As diesel engines develop towards higher efficiency, energy saving, and lightweight designs, traditional cylinder head materials such as gray cast iron and ordinary aluminum alloys are no longer sufficient to meet high-performance demands. Medium-entropy eutectic alloys, with their excellent strength and toughness, good thermal conductivity, and relatively lightweight characteristics resulting from the synergistic effect of multiple principal elements, have become the ideal choice for the next generation of cylinder head materials.
[0003] However, the casting process for medium-entropy eutectic alloy cylinder heads faces numerous challenges: on the one hand, the cylinder head structure is complex, with uneven wall thickness (3~23mm), and multiple hot spots, making it prone to shrinkage porosity and other defects; on the other hand, medium-entropy eutectic alloys have high melting points (1520~1580℃), and their molten metal flow differs from that of traditional alloys, making it difficult for conventional gating designs to achieve stable filling, easily leading to defects such as air entrapment, slag inclusions, and cold shuts. Existing gating designs mainly include bottom-pouring, top-pouring, and single-step designs. Bottom-pouring designs offer stable filling but poor feeding effect, while top-pouring designs provide strong feeding ability but cause significant impact on the mold cavity. Single-step designs are difficult to adapt to the flow characteristics of medium-entropy eutectic alloys and the temperature field uniformity requirements of the complex cylinder head structure. Therefore, existing gating systems fail to adequately adapt to the flow characteristics and solidification features of high-melting-point medium-entropy eutectic alloys, resulting in numerous casting defects and unstable performance. Summary of the Invention
[0004] The purpose of this invention is to provide a composite gating system and casting method for a lightweight, high-strength, and tough diesel engine cylinder head, in order to solve the problem that existing gating systems are difficult to adapt to the characteristics of high-melting-point intermediate-entropy eutectic alloys, resulting in numerous casting defects and unstable performance of the cylinder head.
[0005] The present invention adopts the following technical solution: A composite runner for a lightweight, high-strength, and tough diesel engine cylinder head includes a sprue, a glide runner, a stepped ingate, and a top riser. The lower end of the straight sprue connects to the horizontal sprue; The horizontal gating system connects to the stepped inner gating system; The stepped ingate includes a bottom ingate and a middle ingate. The bottom ingate extends downward from the horizontal runner and is used to connect to the lower part of the diesel engine cylinder head cavity. The middle ingate extends from the horizontal runner and its inlet position is higher than that of the bottom ingate, and is used to connect to the middle part of the diesel engine cylinder head cavity. The top riser is located at the hot spot of the diesel engine cylinder head, and auxiliary risers are also provided in some hot spot areas. Both the top riser and the auxiliary riser are equipped with inclined feeding channels.
[0006] This invention also provides a casting method for a lightweight, high-strength, and tough diesel engine cylinder head, comprising the following steps: Step 1: Prepare the metallic elemental particles of the intermediate entropy eutectic alloy material. After removing impurities and oxides from the surface of the metallic elemental particles, clean them with acetone in an ultrasonic oscillation for 10-15 minutes, and then dry them for later use. Step 2: The external dimensions of the diesel engine cylinder head are designed according to the actual engine model, with a wall thickness of 3~23mm and an average wall thickness of 5~8mm. The composite gating system is assembled to form a complete mold. Step 3: Place the elemental metal particles from Step 1 into a water-cooled copper crucible, and then place the water-cooled copper crucible into a non-consumable vacuum arc melting furnace. Simultaneously, place a titanium ingot of equal weight to the elemental metal particles into another water-cooled copper crucible, and evacuate to a vacuum level ≤5.0×10⁻⁶. -3 After Pa, argon gas is backfilled. First, titanium ingots are melted to reduce the oxygen content in the furnace cavity to 80~100ppm. Then, the metal element particles are melted by electric arc to obtain molten metal. Step 4: Use a composite gating system for pouring. The molten metal enters the mold cavity sequentially through the sprue, gating system, and stepped ingate. The filling time is controlled at 3.5~4.5s. Electromagnetic stirring is performed during the filling process, with a stirring current of 10~15A and a stirring time of 3~5min. Step 5: After casting, solidify sequentially in the order of thin-walled parts, thick-walled parts, and riser feeding system. The solidification time is controlled at 180~220s. After solidification, allow it to cool naturally to room temperature. Then, perform stress-relieving annealing on the casting at a temperature of 700~800℃ and a holding time of 1~2h. Cool with the furnace to obtain the diesel engine cylinder head.
[0007] The beneficial effects of this invention are: This invention addresses the characteristics of high-melting-point medium-entropy eutectic alloys (melting point 1520~1580℃, narrow solidification range, and easy oxidation). It designs a proprietary composite gating system and casting process, employing a stepped structure combining bottom and center gating systems to achieve stable filling and optimized top temperature field. Combined with inclined feeding channels in the top and auxiliary risers, sequential solidification is achieved, reducing shrinkage porosity to below 2%. A conical sprue, trapezoidal runner, filter base, and slag collection bag provide secondary slag control, while electromagnetic stirring improves microstructure uniformity. Through strict control of filling time, flow rate, and annealing treatment, the castings achieve a room temperature tensile strength ≥1290MPa, elongation ≥26%, and density ≤6.44g / cm³. 3 Compared with traditional cast iron cylinder heads, it reduces weight by more than 14.5%, and has a mechanical fatigue life of ≥8 million cycles and a thermal fatigue life of ≥1600 cycles. Attached Figure Description
[0008] Figure 1 This is a schematic diagram of the composite gating system in this invention; Figure 2 This is a schematic diagram of the stepped inner gating system in this invention; Figure 3 This is a schematic diagram of the diesel engine cylinder head casting system model in this invention; Figure 4 This is a schematic diagram of the diesel engine cylinder head product design model in this invention; Figure 5 This is a schematic diagram of a simulation model of the diesel engine cylinder head casting process in this invention; Figure 6 This is a schematic diagram of a simulation model of the diesel engine cylinder head heat treatment process in this invention; Among them, 1. pouring cup, 2. sprue, 3. sprue recess, 4. filter plate base, 5. horizontal sprue, 6. stepped ingate, 7. center ingate, and 8. bottom ingate. Detailed Implementation
[0009] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0010] In one embodiment, a composite gating system for a lightweight, high-strength, and tough diesel engine cylinder head, such as... Figure 1 As shown, the composite gating system includes a straight gating system 2, a horizontal gating system 5, a stepped ingate 6, and a top riser; The lower end of the sprue 2 is connected to the runner 5, and the upper end of the sprue 2 is provided with a pouring cup 1; The horizontal gating 5 is connected to the stepped inner gating 6; like Figure 2 As shown, the stepped ingate 6 includes a bottom ingate 8 and a middle ingate 7. The bottom ingate 8 extends downward from the horizontal runner 5 and is used to connect to the lower part of the diesel engine cylinder head cavity. The middle ingate 7 extends from the horizontal runner 5 and its inlet position is higher than the inlet position of the bottom ingate 8, and is used to connect to the middle part of the diesel engine cylinder head cavity. The top riser is located at the hot spot of the diesel engine cylinder head, and auxiliary risers are also provided in some hot spot areas. Both the top riser and the auxiliary riser are equipped with inclined feeding channels.
[0011] This invention targets the medium-entropy eutectic alloy used in diesel engine cylinder heads. Based on the properties of the medium-entropy eutectic alloy, a dedicated gating system is designed, and a basic connection relationship is constructed between the straight gating 2, the horizontal gating 5, the stepped ingate 6 (including the bottom ingate 8 and the middle ingate 7), and the top riser with an inclined feeding channel. This forms a gating framework adapted to the high melting point and narrow solidification range characteristics of the medium-entropy eutectic alloy. The bottom ingate 8 extends downwards, and the inlet of the middle ingate 7 is higher than that of the bottom ingate 8, laying the foundation for subsequent stepped filling with bottom ingate followed by middle ingate. This effectively avoids the problems of uneven filling or insufficient feeding caused by a single gating method, ensuring the possibility of stable alloy filling and sequential solidification.
[0012] In another embodiment, the sprue 2 adopts a tapered structure that is narrow at the top and wide at the bottom, and its minimum cross-sectional area is 0.5 to 0.8 times the maximum cross-sectional area at the bottom.
[0013] The conical structure of the sprue 2 of this invention can slow down the acceleration of the alloy liquid falling in the sprue 2, reduce the impact and air entrapment tendency, and at the same time achieve the flow resistance effect through the change of cross-sectional area, control the flow rate of the metal liquid entering the horizontal sprue, which is suitable for the characteristics of medium entropy eutectic alloys with weak fluidity at 1520~1580℃, and avoids premature cooling after filling.
[0014] In another embodiment, the horizontal gating 5 has a trapezoidal cross-section structure.
[0015] The trapezoidal cross section has a larger surface area to volume ratio at the same height, which is beneficial for flotation and skimming off oxide inclusions in the molten alloy. At the same time, its wider bottom and narrower top structure enhances the structural stability of the horizontal runner, reduces deformation caused by the scouring of high-temperature molten alloy, extends the service life of the runner, and further improves the secondary slag blocking efficiency.
[0016] In another embodiment, the straight pouring channel 2 is vertically connected to the horizontal pouring channel 5, and the connection point is provided with a straight pouring channel recess 3 and a filter plate base 4.
[0017] The direct sprue recess 3 in this invention can buffer the vertical impact of the molten alloy, making the flow more stable when turning; the filter base 4 forces the molten alloy through the filter, effectively intercepting non-metallic inclusions, especially for the characteristic of medium entropy eutectic alloys that are prone to forming oxide inclusions, significantly improving the purity of the molten alloy and reducing casting inclusion defects.
[0018] In another embodiment, the ratio of the cross-sectional area of the bottom inlet sprue 8 to the cross-sectional area of the middle inlet sprue 7 is 2~3:1; the total cross-sectional area of the stepped inlet sprue 6 is 1.5~2.2 times the flow-blocking cross-sectional area; the bottom diameter of the top riser is 60~80mm and the height is 60~80mm; the height of the auxiliary riser is 20~30mm and the bottom dimensions are 10~20mm×18~25mm, and the auxiliary riser extends to the side by 5~8mm; the inclined feeding channels of the top riser and the auxiliary riser both extend towards the side of the diesel engine cylinder head.
[0019] The numerical parameters designed in this invention ensure that the bottom inlet sprue 8 provides sufficient filling flow without being too fast, and the middle inlet sprue 7 replenishes high-temperature molten metal in a timely manner to establish a favorable temperature gradient. Combined with the precisely sized riser and the inclined feeding channel, effective feeding is achieved at the hot joint of the cylinder head.
[0020] In another embodiment, the radius of the transition arc at the connection between the straight sprue 2 and the horizontal sprue 5 is 8~12mm; a slag collection bag is provided at the connection between the horizontal sprue 5 and the stepped inner sprue 6, and a gap of 50~100mm is left between the slag collection bag and the stepped inner sprue 6; the cross-sectional area of the horizontal sprue 5 in front of the filter base 4 is 1.0~1.3 times the flow obstruction cross-sectional area, and the rear cross-section of the filter base 4 is the smallest cross-section of the entire casting system.
[0021] In this invention, the transition arc radius of 8-12mm reduces eddies and scouring; a 50-100mm gap between the slag collection bag and the ingate allows inclusions sufficient time to rise to the top of the slag collection bag without entering the mold cavity; the filter base 4 has a front cross-sectional area slightly larger than the flow-blocking section and a rear cross-sectional area of minimum size, ensuring that the filter becomes the flow control bottleneck of the entire casting system, thereby stabilizing the filling speed and improving the filtration effect. In another embodiment, the flow-blocking cross-sectional area is calculated using the minimum rising velocity of the molten metal in the mold and the maximum filling time, as shown in the following formula: , Where s is the flow-blocking cross-sectional area, in mm. 2 ; m is the mass of metal passing through the obstruction section, in grams; μ is the flow coefficient from the pouring cup to the obstruction section; ρ is the density of the molten metal, in grams per mm². 3 t is the filling time, in seconds; g is the acceleration due to gravity, in m / s². 2 H represents the average pressure head of the flow-blocking section, in mm.
[0022] This invention also provides a casting method for a lightweight, high-strength, and tough diesel engine cylinder head, such as... Figure 5 As shown, it includes the following steps: Step 1: Prepare the metallic elemental particles of the intermediate entropy eutectic alloy material. After removing impurities and oxides from the surface of the metallic elemental particles, clean them with acetone in an ultrasonic oscillation for 10-15 minutes, and then dry them for later use. Step 2: The external dimensions of the diesel engine cylinder head are designed according to the actual engine model, with a wall thickness of 3~23mm and an average wall thickness of 5~8mm. The composite gating system is assembled to form a complete mold. like Figure 3 and Figure 4 As shown, Figure 3 Model of diesel engine cylinder head casting system. Figure 4 Design model for diesel engine cylinder head products; Step 3: Place the elemental metal particles from Step 1 into a water-cooled copper crucible, and then place the water-cooled copper crucible into a non-consumable vacuum arc melting furnace. Simultaneously, place a titanium ingot of equal weight to the elemental metal particles into another water-cooled copper crucible, and evacuate to a vacuum level ≤5.0×10⁻⁶. -3 After Pa, argon gas is backfilled. First, titanium ingots are melted to reduce the oxygen content in the furnace cavity to 80~100ppm. Then, the metal element particles are melted by electric arc to obtain molten metal. Step 4: Use a composite gating system for pouring. The molten metal enters the mold cavity sequentially through the straight gating system 2, the horizontal gating system 5, and the stepped ingate system 6. The filling time is controlled at 3.5~4.5s. Electromagnetic stirring is carried out during the filling process, with a stirring current of 10~15A and a stirring time of 3~5min. Step 5: After casting, solidify sequentially in the order of thin-walled parts, thick-walled parts, and riser feeding system. The solidification time is controlled at 180~220s. After solidification, allow it to cool naturally to room temperature. Then, perform stress-relieving annealing on the casting at a temperature of 700~800℃ and a holding time of 1~2h. Cool with the furnace to obtain the diesel engine cylinder head.
[0023] like Figure 6 As shown, Figure 6 A simulation model of the diesel engine cylinder head heat treatment process was presented.
[0024] The current control method for arc melting in step 3 is as follows: increase the current from 80A at the initial arc ignition to 200A. After the metal particles have initially melted, increase the current to 500~550A at a rate of 50A / min and maintain it for 3~5min. Then, decrease the current at a rate of 50A / min until the power is cut off and the cooling is achieved. The melting process is repeated 5~6 times.
[0025] Step 4 is as follows: In the stepped ingate 6, the bottom ingate 8 first guides the molten metal to fill the lower part of the cavity smoothly. When the liquid level rises to the position of the middle ingate 7, the middle ingate 7 begins to inject molten metal to optimize the top temperature field. During the pouring process, the flow rate of the molten metal is controlled at 0.15~0.25m / s.
[0026] The room temperature performance indicators of the diesel engine cylinder head castings prepared by the above method are as follows: tensile strength ≥1290MPa, yield strength ≥400MPa, elongation ≥26%, elastic modulus ≥190GPa, and thermal conductivity ≥32W / (m·K); the high temperature performance indicators at 600℃ are as follows: tensile strength ≥520MPa, yield strength ≥360MPa, elongation ≥8%, and thermal conductivity ≥62W / (m·K); mechanical fatigue life ≥8 million cycles, thermal fatigue life ≥1600 cycles, and density ≤6.5g / cm³. 3 .
[0027] The effects of the present invention will be described in detail below with reference to the embodiments.
[0028] Example 1 This embodiment uses (Ni5Al2) 55 Fe 45 Taking a medium-entropy eutectic alloy as an example, this alloy has a two-phase structure of B2-NiAl phase and FCC phase, with a melting point of about 1550℃. The specific process for preparing a lightweight, high-strength and tough diesel engine cylinder head includes: Step 1: Prepare metal element particles according to the atomic percentages Fe: 45%, Ni: 39.3%, Al: 15.7%, with a metal element purity ≥ 99.99%. After removing surface impurities and oxides, clean them with acetone in an ultrasonic oscillation for 12 minutes, and then dry them for later use. Step 2: The cylinder head is designed with external dimensions of 671mm×645mm×294mm, wall thickness of 3~23mm, average wall thickness of 6mm, and a composite gating system is assembled to form a complete mold. Step 3: Place the elemental metal particles from Step 1 into water-cooled copper crucible No. 2, and place crucible No. 2 into a non-consumable vacuum arc melting furnace. Simultaneously, place the titanium ingot into water-cooled copper crucible No. 1, and evacuate to a vacuum level of 5.0 × 10⁻⁶. -3 After Pa, argon gas is backfilled, and titanium ingots are melted first to reduce the oxygen content in the furnace cavity to 90 ppm. Step 4: Increase the arc melting current from 80A at the initial arc ignition to 200A. After the metal particles have initially melted, increase it to 520A at a rate of 50A / min and maintain it for 4 minutes. Then decrease the current at a rate of 50A / min until the power is cut off and the cooling is completed. Repeat the melting process 5 times to obtain a uniform medium-entropy eutectic alloy liquid. Step 5: A composite gating system is used for casting. The minimum cross-sectional area of the sprue is 0.6 times the maximum cross-sectional area of the lower part. The horizontal gating has a trapezoidal cross-section (top base 35mm, bottom base 50mm, height 75mm). The cross-sectional area of the horizontal gating in front of the filter base is 1.2 times the flow-blocking cross-sectional area. In the stepped ingate, the ratio of the cross-sectional area of the bottom ingate to the middle ingate is 2.5:1, and the total cross-sectional area of the ingate is 1.8 times the flow-blocking cross-sectional area. The medium-entropy eutectic alloy liquid enters the mold cavity sequentially through the sprue, horizontal gating, and stepped ingate. The filling time is controlled at 4.0s. Electromagnetic stirring is performed during the filling process with a stirring current of 12A and a stirring time of 4min. Step 6: The top riser is set at the hot spot of the cylinder head, with a bottom diameter of 70mm and a height of 70mm. An auxiliary riser with a height of 25mm and a bottom size of 15mm×22mm is added in the hot spot area of the thin-walled boss. The riser extends 6mm to the side and is provided with an inclined feeding channel. After the casting is completed, solidification is carried out in sequence according to the order of thin-walled part, thick part, and riser feeding system. The solidification time is controlled within 200s. After solidification, it is allowed to cool naturally to room temperature. Step 7: Anneal the casting at 750℃ for 1.5 hours, then cool it to room temperature in the furnace to obtain the finished diesel engine cylinder head.
[0029] Example 2 The specific steps in this embodiment are the same as those in Embodiment 1, except that: In step 5, the filling time is controlled at 3.7s, the electromagnetic stirring current is 10A, and the stirring time is 3min; in step 7, the annealing temperature is 700℃ and the annealing time is 1h.
[0030] Example 3 The specific steps in this embodiment are the same as those in Embodiment 1, except that: In step 5, the filling time is controlled at 4.3s, the electromagnetic stirring current is 14A, and the stirring time is 5min; in step 7, the annealing temperature is 780℃ and the annealing time is 2h.
[0031] Table 1. Comparison of performance test results of cylinder head products prepared in Examples 1-3 The cylinder head products prepared in Examples 1-3 were subjected to comprehensive performance tests. The test results are shown in Table 1. As can be seen from Table 1, the embodiments of the present invention are significantly superior to traditional cast iron cylinder heads in terms of lightweight, toughness, high temperature performance and fatigue life, and the defect rate is greatly reduced.
Claims
1. A composite gating system for a lightweight, high-strength, and tough diesel engine cylinder head, characterized in that, It includes a straight sprue (2), a horizontal sprue (5), a stepped inlet sprue (6), and a top riser; The lower end of the straight sprue (2) is connected to the horizontal sprue (5); The horizontal gating channel (5) is connected to the stepped inner gating channel (6); The stepped ingate (6) includes a bottom ingate (8) and a middle ingate (7). The bottom ingate (8) extends downward from the horizontal runner (5) and is used to connect to the lower part of the diesel engine cylinder head cavity. The middle ingate (7) extends from the horizontal runner (5) and its inlet position is higher than that of the bottom ingate (8), and is used to connect to the middle part of the diesel engine cylinder head cavity. The top riser is located at the hot spot of the diesel engine cylinder head, and auxiliary risers are also provided in some hot spot areas. Both the top riser and the auxiliary riser are provided with inclined feeding channels.
2. The composite gating system for a lightweight, high-strength, and tough diesel engine cylinder head according to claim 1, characterized in that, The straight gating channel (2) adopts a tapered structure that is narrow at the top and wide at the bottom, and its minimum cross-sectional area is 0.5 to 0.8 times the maximum cross-sectional area at the bottom.
3. The composite gating system for a lightweight, high-strength, and tough diesel engine cylinder head according to claim 2, characterized in that, The horizontal gating system (5) has a trapezoidal cross-section structure.
4. The composite gating system for a lightweight, high-strength, and tough diesel engine cylinder head according to claim 3, characterized in that, The straight pouring channel (2) is vertically connected to the horizontal pouring channel (5), and the connection point is provided with a straight pouring channel recess (3) and a filter plate base (4).
5. The composite gating system for a lightweight, high-strength, and tough diesel engine cylinder head according to claim 4, characterized in that, The ratio of the cross-sectional area of the bottom inlet runner (8) to that of the middle inlet runner (7) is 2~3:1; the total cross-sectional area of the stepped inlet runner (6) is 1.5~2.2 times the flow-blocking cross-sectional area; the bottom diameter of the top riser is 60~80mm and the height is 60~80mm; the height of the auxiliary riser is 20~30mm and the bottom size is 10~20mm×18~25mm, and the auxiliary riser extends to the side by 5~8mm; the inclined feeding channels of the top riser and the auxiliary riser both extend to the side of the diesel engine cylinder head.
6. The composite gating system for a lightweight, high-strength, and tough diesel engine cylinder head according to claim 5, characterized in that, The radius of the transition arc at the connection between the straight gating (2) and the horizontal gating (5) is 8~12mm; a slag collection bag is provided at the connection between the horizontal gating (5) and the stepped inner gating (6), and a gap of 50~100mm is left between the slag collection bag and the stepped inner gating (6); the cross-sectional area of the horizontal gating (5) in front of the filter base (4) is 1.0~1.3 times the flow obstruction cross-sectional area, and the rear end section of the filter base (4) is the smallest cross-section of the entire casting system.
7. The composite gating system for a lightweight, high-strength, and tough diesel engine cylinder head according to claim 6, characterized in that, The flow-blocking cross-sectional area is calculated using the minimum rising velocity of the molten metal in the mold and the maximum filling time, and the calculation formula is as follows: ， Where s is the flow-blocking cross-sectional area, m is the mass of metal passing through the flow-blocking cross-section, μ is the flow coefficient from the pouring cup to the flow-blocking cross-section, ρ is the density of the molten metal, t is the filling time, g is the gravitational acceleration, and H is the average pressure head of the flow-blocking cross-section.
8. A casting method for a lightweight, high-strength, and tough diesel engine cylinder head utilizing the composite gating system described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1: Prepare the metal elemental particles of the intermediate entropy eutectic alloy material. After removing impurities and oxides from the surface of the metal elemental particles, clean them with acetone in an ultrasonic oscillation for 10-15 minutes, and then dry them for later use. Step 2: The external dimensions of the diesel engine cylinder head are designed according to the actual engine model, with a wall thickness of 3~23mm and an average wall thickness of 5~8mm. The composite gating system is then assembled to form a complete mold. Step 3: Place the elemental metal particles from Step 1 into a water-cooled copper crucible, and then place the water-cooled copper crucible into a non-consumable vacuum arc melting furnace. Simultaneously, place a titanium ingot of equal weight to the elemental metal particles into another water-cooled copper crucible, and evacuate to a vacuum level ≤5.0×10⁻⁶. -3 After Pa, argon gas is backfilled. First, titanium ingots are melted to reduce the oxygen content in the furnace cavity to 80~100ppm. Then, the metal element particles are melted by electric arc to obtain molten metal. Step 4: The composite gating system is used for casting. The molten metal enters the mold cavity sequentially through the straight gating system (2), the horizontal gating system (5), and the stepped inlet gating system (6). The filling time is controlled at 3.5~4.5s. Electromagnetic stirring is performed during the filling process. The stirring current is 10~15A and the stirring time is 3~5min. Step 5: After casting, solidify sequentially in the order of thin-walled parts, thick-walled parts, and riser feeding system. The solidification time is controlled at 180~220s. After solidification, allow it to cool naturally to room temperature. Then, perform stress-relieving annealing on the casting at a temperature of 700~800℃ and a holding time of 1~2h. Cool with the furnace to obtain the diesel engine cylinder head.
9. A casting method for a lightweight, high-strength, and tough diesel engine cylinder head according to claim 8, characterized in that, The current control method for arc melting in step 3 is as follows: increase the current from 80A at the initial arc ignition to 200A, and after the metal particles have initially melted, increase the current to 500~550A at a rate of 50A / min, maintain it for 3~5min, and then decrease the current at a rate of 50A / min until the power is cut off and the cooling is achieved. The melting is repeated 5~6 times.
10. A casting method for a lightweight, high-strength, and tough diesel engine cylinder head according to claim 8, characterized in that, Step 4 specifically involves the following steps: In the stepped inlet gate (6), the bottom inlet gate (8) first guides the molten metal to fill the lower part of the cavity smoothly. When the liquid level rises to the position of the middle inlet gate (7), the middle inlet gate (7) begins to inject molten metal to optimize the top temperature field. During the pouring process, the flow rate of the molten metal is controlled at 0.15~0.25m / s.