Die-casting aluminum is based on the sky and dragon slaying
In the past period of time, under the goal of "double carbon", new energy vehicles have become an important support for the automobile industry. The ultra-large integrated body structural parts prepared by heat-free die-casting aluminum alloy have also become a hot spot for major OEMs. Therefore, the development and application of heat-free high-strength and high-toughness die-casting aluminum alloy materials and iterative upgrades will further broaden the application scenarios of die-cast aluminum alloys in the new energy automobile industry and contribute material strength to the automotive revolution.
So how to find the right material in the uneven die-casting aluminum alloy? To quote a phrase from Jin Daxia, it is: the supreme martial forest, the sword slays the dragon, commands the world, dare not follow, rely on the sky, who fights with the front. I believe that everyone's eyes have already locked in heat-free high-strength and high-toughness die-cast aluminum alloys. However, both the Heavenly Sword and the Dragon Slayer Sword could only play their real role under the use of martial arts masters. In short, heat-free high-strength and high-toughness die-cast aluminum alloys are actually a complete solution, from the composition of the alloy to the die casting process, as well as the combination of mold and equipment are related. To achieve the true essence of integration and complementarity. Therefore, many wishful thinking 'composition reproduction' can not achieve the desired results on the parts, and the parts produced will have obvious defects such as a sharp decline in mechanical properties and thermal cracking.
Heat-free die-cast aluminum alloy material from Peng Liming's team at Jiaotong University
▲Figure Professor Peng Liming, doctoral supervisor of the School of Materials Science and Engineering, Shanghai Jiaotong University
(1) Alloy system: Al-Si
(2) Alloy characteristics:
A. JDA1b contains ~9wt.% Si element, which ensures the excellent die-casting process performance of the alloy (Table 1). The flow verification results show that JDA1b alloy is more than 15% higher than that of the same grade material, the higher Si content makes the shrinkage rate of JDA1b alloy low, and the above alloy characteristics ensure the extensiveness of the alloy process window and the smooth filling and demolding process.
b. Taking the control of alloy structure as the starting point (Figure 1), the innovative introduction of trace elements to deteriorate and refine the tissue to ensure that the alloy structure is small and dispersed, and to ensure the strength and plasticity of the alloy. Considering the heat-free treatment performance, casting properties and die-casting processability, the material reaches a mechanical property of yielding 130-150MPa, tensile resistance of 260-300MPa and elongation of 12-15% under the casting state (Figure 2);
c. Good machinability, good weldability and polishing performance, no need for heat treatment conventional die casting can achieve Silafont36/AlSi10MnMg material SQ-T7 after heat treatment performance;
Typical alloy applications:
a、JDA1b alloy shock absorber:
Figure 3 shows a shock tower part prepared from a JDA1b heat-free alloy. The results of the bulk performance test conducted in 12 different positions of the shock absorption tower show that the elongation of the body is 8.6% at the end of the filling position, and the elongation is greater than 9.5% in the other 11 body positions. The average yield strength of the 12-position body > 130MPa, the tensile strength > 260MPa, and the elongation >10%.
b、 JDA1b alloy integrated super casting:
Recently, the TechCastTM low-carbon aluminum alloy material integration super die casting jointly developed by the National Engineering Center of Light Alloy of Shanghai Jiao Tong University and Huaren Yuntong Gaohe Automobile has officially obtained mass production application. TechCastTM is a heat-free die-cast aluminum alloy optimized by combining the characteristics of JDA1b alloy with the characteristics of Huaren Express's integrated oversized castings. After multiple rounds of R&D research and part verification, it has achieved 100% forward development of the whole process in terms of material development, performance optimization, manufacturing process and system integration verification, and has excellent performance in material die casting performance, mechanical properties, manufacturing performance, environmental durability and other indicators. The fluidity of the material is more than 15% higher than that of the same level of material, and the strong plastic product is more than 30%, which ensures that the performance of the whole vehicle collision reaches a higher dimension.
Peng Liming's team has other heat-free die-cast aluminum alloy materials
After years of development and accumulation, academician Ding Wenjiang and Professor Peng Liming of the Light Alloy Center of Shanghai Jiao Tong University have successfully developed heat-free treatment die-cast aluminum alloy materials with 2 alloy systems and 5 subtypes to meet the needs of different performance and application scenarios. Among them, JDA1x is the Al-Si-X system and JDA2x is the Al-Mg-X system. The mechanical properties of the five alloys are shown in Table 2 below. From the comparison of alloy properties in the table, it can be found that JDA die-cast aluminum alloy materials can achieve excellent mechanical properties in the casting state to meet the performance requirements of parts and components in different application scenarios. Table 3 shows the casting performance parameters of JDA alloy part.
JDA1 alloy has been successfully applied to more than a dozen support-type stressed structural parts in the field of passenger cars and commercial vehicles.
JDA1b alloy is mainly used in batches for integrated body structural parts due to its excellent casting and strong plasticity, and at the same time covers a large number of body structural parts produced by heat-treated die-cast aluminum alloys of the original material.
JDA1c alloy due to its high casting strength, especially yield strength, is mainly used in motor housing and other high-strength requirements castings, thereby increasing the possibility of structural optimization in the part design process, improving the size deformation of parts in the actual production process, low pass rate and other issues.
JDA2 system alloy is mainly used in chassis parts due to its high strength and toughness characteristics, which meets the high impact and fatigue durability requirements of castings. In addition, the JDA2 system alloy has a typical thin-walled effect, and the alloy has a wide application prospect in the field of large thin-walled body structural parts.
brief summary
Nowadays, China's new energy automobile industry is developing at a high speed, and super-large integrated body structural parts have become a hot spot for major OEMs. In the process of integrated casting design and preparation, it is necessary to comprehensively consider the characteristics of parts, the characteristics of heat-free materials, the mold structure of parts, the die casting process and the ability of the machine. In particular, heat-free treatment of high-strength and high-toughness die-casting aluminum alloy materials, as a key part of the integrated casting, must be integrated into the part design (regionalized performance differences of large castings), mold design (material fluidity and parts local characteristics of fine design) and follow-up process optimization, in order to achieve continuous and stable production of high-quality integrated castings, and promote the integrated design of integrated parts of the whole vehicle in the industrial chain, the research and development of transformative materials and the iterative upgrading of giant die-casting equipment.
The only main body of material business operation is Fengyang Ailes Light Alloy Precision Forming Co., Ltd
Fengyang Aers Light Alloy Precision Forming Co., Ltd. (formerly known as Shanghai Light Alloy Precision Forming National Engineering Research Center Co., Ltd.) is a national high-tech enterprise specializing in the research and development and application of high-performance lightweight materials and industrialization, process technology integration, which was approved by the State Development Planning Commission and relied on Shanghai Jiaotong University, and was established in Songjiang, Shanghai in December 2001. In 2010, in order to expand the scale of production, through industrial planning and layout, Fengyang Airs Light Alloy Precision Forming Co., Ltd., which is responsible for the function of manufacturing center, was established in Fengyang County Industrial Park, Anhui Province, covering an area of 160 acres with a total investment of 250 million yuan. With light alloy materials and processing technology as the research goal, it is committed to the research and development and industrialization of high-performance light alloy materials, precision molding, and surface treatment, and provides one-stop solutions for the lightweighting and energy-saving of aerospace, transportation, electronic communications, power appliances, medical equipment and other industry products. GM, Toyota, Volkswagen, Peugeot, Bridgestone, Emerson, ABB, AVIC, ZTE, SAIC New Energy, Dongfeng Motor, Jacques Motor and other well-known brands have become partners of Fengyang Aers.