Appreciation of high-quality die-casting parts at the 2024 China Die-casting Annual Conference

Appreciation of castings one

Casting name:

PHEV gearbox housing

This product is a key component of the gearbox of hybrid models - the external shell part, which plays the role of supporting and protecting gear bearings.

1. Parts need to be directly formed by Buhler 4400 tons of die casting, parts size 598.5*513.4*239(mm);

2. Product cleanliness requirements:

Inner cavity: weight of impurities ≤10mg (20um for filter), residual metal foreign body size < 600um, non-metal foreign body size < 1500um;

Oil passage: weight of impurities ≤2mg (20um for filter screen), residual metal foreign body size < 400um, non-metal foreign body size < 600um;

3. High machining requirements, such as:

(1) Dual control of bearing holes installed in the product, relative to the position of the benchmark requirement of 0.06 at the same time, the relative spacing of bearing holes is 91±0.017mm, 141.5±0.02mm, 93±0.017mm, etc.

(2) Installation bearing hole diameter and cylindricity requirements are high: such as diameter φ80 (-0.016, -0.033) mm, cylindricity requirements 0.018;

③ Aluminum alloy products die casting installation steel sleeve, machined steel sleeve hole diameter φ55 (+0.019, 0) mm, processing depth requirements 159 (+0.05, 0) mm;

④ Other dimensions such as cylindricity 0.015, verticality 0.015, aperture φ72 (+0.025, +0.005) mm and so on.

Key technologies and innovations:

1. Vacuum punch + automatic lubrication system is selected, micro-spraying device of release agent for new aluminum alloy die-casting is adopted, and extrusion pin molding scheme is adopted;

2. Horizontal fixture, fixture hollow so that different sides of the product in the same order to complete processing, to ensure the size;

3. Shell processing line, the use of professional customized Mazak clamping machine, special tools, and blank constant temperature, cutting fluid constant temperature. Online monitoring probes are added to each sequence to ensure dimensional stability. And put into the special CNC automatic production line, from the blank feeding, to the completion of CNC processing, fully mechanized, to ensure product dimensional stability.

Appreciation of castings II

Casting name: inverter shell

This product is an automotive inverter housing, requiring good heat dissipation and strict air tightness to protect important electronic components in the housing:

1. Casting application: automotive inverter;

2. Typical features of casting products: thin wall, deep cavity, complex structure, safety, sealing;

① Part of the product position mold inclined top forming;

② The appearance of some products is strict, the roughness of the blank is required to be below Ra6.3, and casting points and burns are not allowed;

③ Parts need to be directly formed by UBE 2200/1650 tons of die casting, and then combined shipment;

④ Product cleanliness requirements: weight of impurities ≤1.5mg, size of foreign bodies < 1000um;

3. Product key requirements:

①100% chromate conversion coating (passivation), 96-hour salt spray requirements, appearance in line with GBT 6461-2002 grade 8 or above;

② Leak detection pressure: watercourse: 35PSI large cavity: 6PSI

Cavity leakage: Water channel: 1cc/min Large cavity: 2cc /min

100% helium detection: cooling channel 2.5bar, helium concentration is not less than 85%, the value is not higher than 1*10-7 mbar*L/S;

③ Product processing line, the use of heat shrink tool handle, 280mm avoidance length processing products, the tool handle has high stability and coaxial degree, to ensure product accuracy and size.

Participating enterprise: Ningbo Daxie Development Zone Tianzheng Mold Co., LTD

Appreciation casting

Casting name:

Magnesium alloy subframe

Subframe is a suspension form, which is an intermediate component connecting the suspension system and the body, which can improve the comfort and safety of the vehicle and the connection stiffness of the suspension system.

Because the product has very high tensile strength, yield strength and elongation, the mold adopts high vacuum design, so that the performance of the vacuum valve is well reflected, and the vacuum degree in the mold cavity is minimized. Considering that the vacuum structure of the cylinder is very difficult to achieve, two vacuum hydraulic valves are used to pre-pump the mold to improve the vacuum degree of the inner cavity, and two sets of mechanical valves are used at the same time during the die casting process to ensure that the vacuum degree of the inner cavity is kept low during the whole die casting process.

Because the product material is Mg alloy, the mold temperature oil heating structure is used in the design to ensure that the material temperature of the casting in the filling process meets the die casting conditions. At the same time, FLOW-3D and MAGMA software were repeatedly used in the design process to perform mold FLOW analysis and heat balance analysis for the casting and mold, and the oil circuit was repeatedly optimized while optimizing the casting and mold to avoid high temperature difference and hot node.

Participating enterprise: FAW Casting Co., LTD

Appreciation casting

Casting name:

Magnesium alloy hybrid battery housing under the box

Using FAW casting and forging self-developed high performance magnesium alloy material, through high vacuum die casting process, the integrated water jacket magnesium alloy hybrid battery lower box development, compared with aluminum alloy battery lower box weight reduction of 30.7%. The lower housing of magnesium alloy battery was prepared by friction stir welding. This product overcomes two technical problems of magnesium alloy integrated water jacket high vacuum die casting process and magnesium alloy friction stir welding.

Participating enterprise: Dalian Yaming Auto Parts Co., LTD

Appreciation of castings one

Casting name: runner plate

Heat pump air conditioning is the most effective solution for pure electric vehicle heating.

Battery anxiety of pure electric vehicles has been a pain point for consumers, in the case of no breakthrough in battery technology, heat pump air conditioning efficiency factor is 2-3 times higher than PTC heating, can effectively extend the range of more than 20%.

The runner plate is the key core component, which can withstand the high temperature of 600 degrees brazing.

Appreciation of castings II

Casting name:

Brazing refrigerant liquid cooling plate

The requirements of sex:

Tensile strength >150MPa, yield strength >100MPa, elongation >1.5%

Application market:

Thermal management systems and cooling systems for the automotive and communications sectors

Newly developed material system and performance strengthening technology, innovative die casting production process, aluminum alloy die casting can be brazed at high temperature, and can meet the high pressure and high sealing engineering application scenarios. Among them, the blasting pressure of brazing assembly can reach more than 13MPa; The leakage rate of sealing test can be as low as E-10 Pa.m3/s.

Participating enterprise: Sheng Sai Si Precision Die Casting (Yangzhou) Co., LTD

Appreciation of castings one

Casting name:

Steering gear main housing

This product is the core component of the automobile steering system, which is the device for the driver to control the steering of the vehicle through the steering wheel. It plays the role of fixing and protecting the parts and hydraulic system inside the steering gear, and can also increase the rigidity of the steering gear and improve the response speed of the steering gear.

■ Product application: automobile steering gear;

■ Product features: die-casting integrated molding, complex structure, part of the use of internal pumping molding. Use force 1250T die-casting direct molding, part size 662*188.3*167.8 (mm);

■ Product cleanliness requirements: weight of impurities ≤5mg (5um for screen), residual metal and non-metal particle size ≤650um;

■ High processing requirements: mounting hole φ34.963±0.013mm, coaxiality 0.06, verticality 0.05;

■ Product key requirements: The use of five-axis CNC machine tool processing, a clamping machining of the left and right parts to ensure accuracy and size; 100% leak detection. Required pressure 1.4±0.3bar, leakage ≤ 8cc/min.

Appreciation of castings II

Casting name:

EBS double channel control valve main housing

This product is the core component of automobile brake system. The body is symmetrical on both sides and is used to assemble the relay valve assembly for independent control on both sides. The top of the valve body is connected by screws for mounting the controller assembly. The bottom of the valve body is connected by a clip for mounting the muffler assembly.

■ Product application: assembled on the trailer, used to achieve the trailer ABS, RSS function of the product;

■ Product features: The product has versatility, complexity, safety, flexibility, etc. Product design is difficult, burr and aluminum chip control requirements are very strict; Product plugging, assembly sealing requirements are high;

■ Product salt spray test requirements: according to the national standard GB/T 10125 neutral salt spray test requirements of the product for 72h continuous spray, after the test is completed, the product is required to be free from red rust for 72h. The area of the black spot is less than 10% of the total area, and more than one corrosion substance with a diameter greater than 2mm should not be produced;

■ High processing requirements: dynamic seal requires a roughness of 0.8, static seal requires a roughness of 1.6, the product involved in the form and position tolerance dimensions including flatness, perpendicularity, concentricity, etc. are 0.1, the difficulty is high;

■ Surface treatment: surface oxidation treatment, oxide film thickness: 0.2-0.5um; Test the appearance color of the product according to GB/T 14952.3-1994 "Aluminum anodized film visual method", and the color difference should be within the color scale or refer to the color of the sealed sample.

Participating enterprise: General Research Institute of Mechanical Science (JILE) Semi-solid State Technology Research Institute Co., LTD

Appreciation of castings one

Casting name:

Body bracket

The product is a new energy intelligent heavy truck body bearing structural parts, achieve aluminum instead of steel, weight reduction of 50%, the casting is prepared by liquid die forging process, T6 heat treatment strengthening, 100% ray secondary flaw detection.

Parts lightweight, integration is the current development trend of the industry. For light alloy castings with complex shape, mechanical properties and high internal quality requirements, defects are still easy to occur in some pin hole parts or parts with large wall thickness changes, which limits the improvement of batch production pass rate. In this context, the company uses large-scale extrusion casting equipment with independent intellectual property rights, through fixed-point strong cooling and local feeding and other process optimization, the metal filling control and the operating system of the equipment are adapted to be integrated, providing support for the efficient preparation of high-performance aluminum alloy parts with complex structures.

Appreciation of castings II

Casting name: hand model

The casting is jointly developed by semi-solid Research Institute and Xiamen Genel Company. Medical rubber, nitrile gloves, the primary tooling - hand model, has always used ceramic type, although it can meet the functional requirements, but its energy consumption, easy to break, no recovery and other shortcomings, the use of easy to recycle metal type has become a research hotspot, aluminum alloy with its light weight has become the first choice. However, because the hand mold parts have thin walls and complex cavities, they need to be welded with profiles, and use heat (200-300℃ repeated heat) and other special requirements, and there are many problems in the preparation of various schemes such as ordinary die casting and profile stamping, which can not meet the requirements of production projects. Based on the common coated sand core, a high temperature heat treatment and argon arc welding hand mold cavity casting has been successfully developed by using the uniformly accelerated cylinder impregnation semi-solid die casting technology, which solves the limitations of complex salt core manufacturing process and high cost to a certain extent, and lays a solid foundation for mass production of high-quality, efficient and low-cost cavity die casting parts, and has broad application and development prospects.

Participating enterprise: Ningbo Fenda New Energy Technology Co., LTD

Appreciation of castings one

Casting name:

Electric control box

The successful die casting mold development of the electric control box shell of new energy electric vehicles is a huge system project that integrates and uses a number of technical systems such as materials, heat treatment, mold design, die casting process, processing, assembly process, management, and quality control. Die-casting process design is a very important part, the rationality of the process directly affects the quality of castings and subsequent production and processing links. The shell structure of electric control box is complicated and the internal quality is high. For example, thread processing does not allow rotten teeth, porosity requirements ≤2%. For this kind of complex die casting, a good die casting process design scheme plays a decisive role in the quality of the product.

In view of the difficulties, the company adopts the casting system design and vacuum scheme. The die casting mold works under high temperature and high pressure environment, which requires high die material and thermal fatigue resistance, complex structure, large wall thickness difference, and leakage test under high pressure. Therefore, the defects such as gas shrinkage holes and sticky molds that can lead to leakage in the casting process should be avoided first. The casting system selected in line with the requirements of the die casting process, especially the position and orientation of the inner gate, should make the metal liquid flow smooth and orderly remove the gas in the cavity, so as to achieve good filling effect and avoid the purpose of die casting defects. Through the analysis of the structure and performance requirements of the product, the pouring design is carried out. Firstly, casting simulation software was used to conduct numerical simulation analysis of filling, particle tracking, air pressure, temperature, solidification and other processes of the product pouring and overflow system. Secondly, the rationality of the scheme design was confirmed according to the analysis results. Finally, the rationality of the process design scheme was verified through the production test.

Appreciation of castings II

Casting name:

Water cooling plate

The early design and development of the new energy vehicle console water cooling plate adopts machining center precision carving, greatly reducing the development cycle of the production of molds and tooling time, and reducing the design changes of uncertain factors. If you want to change the shape and size of the parts, you only need to modify the parts processing program, and the processing quality is stable, the processing accuracy is high, and the repetition accuracy is high. The production efficiency is higher in the case of multi-variety and small-batch production, which can reduce the time of production preparation, machine tool adjustment and process inspection. Suitable for product test stage, sample, suitable for this part or similar development and modification, after R & D to confirm the size is stable for mold development and mass production.

In addition, this part adopts the friction stir welding process of the water channel cover plate. In the welding process, the stirring head moves along the seam of the welding workpiece while rotating. The friction heat generated by this movement and the mechanical agitation effect cause the temperature of the material in the connection part to rise and soften. The high-speed rotation of the mixing head and the friction between the shoulder and the workpiece surface generate heat, which is not only used to prevent the overflow of the material in the plastic state, but also to remove the oxide film on the surface. Under the action of high-speed rotation and movement of the stirring head, the aluminum parts begin to plasticize, and with the movement of the stirring head, the plasticized materials flow and deposit on the back of the stirring head, and finally form a dense solid weld to achieve the welding seal effect.