According to SmarTech's prediction, aluminum alloys account for the consumption of all metal powders in metal 3D printing (calculated by volume) from 5.1% in 2014 to 11.7% in 2026. The 10-year compound growth rate of aluminum alloys in the automotive industry At 51.2%.
In the field of automobile manufacturing, aluminum alloy is the main force to achieve light weight. The research data released by the famous consulting company Daktronics shows that the average aluminum consumption in Europe has tripled since 1990, from 50kg to the current 151kg. And will increase to 196kg in 2025. [1]
Lightweighting is not just about reducing weight, it is about balancing the performance, safety, cost and weight of the vehicle. The requirements for the manufacture of automotive aluminum alloy parts include meeting crash performance and effectiveness in different situations. However, the current aluminum alloy additive manufacturing process design is mainly capable of manufacturing materials with high resistance but not high toughness, and high elongation at break is particularly important to meet the performance requirements of automobile collisions.
The German automotive engineering company EDAG unites eight partners in the fields of materials, scientific research, additive manufacturing, and simulation.
Not just lightweight
In the past three years, EDAG and partners have studied the complete aluminum alloy additive manufacturing process chain including powder manufacturing, simulation, and part development.
Among the eight partners, the work carried out by the Fraunhofer Institute (IAPT) and GE Additive is based on powder bed laser melting (LBM) technology to develop the additive manufacturing process of this new aluminum alloy material. The Fraunhofer Institute (ITWM) simulated the rapid cooling of materials during the additive manufacturing process. Car manufacturers Mercedes-Benz and EDAG have carried out performance simulation with the support of simulation company Altair.
The above columns focus on the research of the new aluminum alloy material additive manufacturing process chain, and the goal is to achieve mass production of lightweight automotive parts. In the experimental stage, EDAG and project partners have studied different alloy materials, and the materials that best meet the needs of the target have been tested on different laser melting 3D printing systems.
According to EDAG, the uniqueness of the alloy is its versatility. A single alloy can create a wide range of properties, which can be flexibly adjusted by downstream heat treatment processes. EDAG generates material maps based on the determined material parameters, and uses Altair OptiStruct software to optimize the structure, reduce the weight of equipotential components, and consider the requirements in the additive manufacturing process.
EDAG selected a variety of automotive components for optimization. The results show that complex components with high stiffness requirements in the dynamic high-load wheel frame and wheel arch area can also achieve effective weight loss. Some of these components lost 30% of their weight, exceeding expectations. Since the manufacturing method of these components is metal 3D printing technology, which can flexibly meet mass customization, these components can be designed according to the load level requirements of different vehicles.
The new aluminum alloy research and development partners have given a positive affirmation to this aluminum alloy material, which will be available in a few months under the trademark CustAlloy®. EDAG said that CustAlloy® meets the requirements of the automotive industry in terms of strength, ductility, and corrosion resistance, and will become a 3D printing material suitable for the mass production of lightweight and collision-resistant parts for automobiles. The additive manufacturing process developed by EDAG for this material and the proven simulation method are all effective tools to help users use this material for mass production of parts.
3D printing technology can solve the extremely complex and difficult problem of manufacturing precision components. It has inherent advantages in complex structural problems such as conformal inner flow channels, complex thin walls, lattice hollowing, complex internal cavities, and multi-component integration. It is a fast 3D printing technology An important area of development.
In the application of 3D printing aluminum alloys, due to the forming characteristics of traditional aluminum alloys, most grades are not suitable for 3D printing. There are only a few cast aluminum grade alloys suitable for 3D printing, such as AlSi10Mg and AlSi7Mg.
In 2019, aluminum alloy 3D printing materials have made significant progress, mainly reflected in the emergence of new high-strength 3D printed aluminum alloy materials. The following three high-strength aluminum alloy new materials are quite typical:
The Monash University research team led by the founder of SZBF Alloy Technology Company and academician Dr. Wu of the Australian Academy of Engineering has successfully developed a special aluminum alloy material with the brand of Al250C for high strength and high toughness additive manufacturing. The highest level, the yield strength can reach 580MPa, the tensile strength is more than 590MPa, and the elongation can reach 11%. Using this material to make aviation aluminum alloy 3D printed structural parts, it is more promising to replace some of the titanium alloy components currently in aerospace to achieve aerospace. The purpose of reducing weight and saving cost in aviation.
The British casting company Aeromet International has manufactured parts with aluminum alloy powder A20X that have exceeded the ultimate tensile strength (UTS) of 500 MPa. Aeromet said that this achievement made the aluminum alloy material "one of the strongest aluminum alloy powders commercially available for additive manufacturing."
In October 2019, HRL Lab officially launched the developed high-strength 7A77.60L aluminum powder for 3D printing on the market. The formed material is crack-free and equiaxed (that is, the grains are approximately equal in length, width, and height), achieving a fine-grain microstructure and having material strength comparable to that of forged materials. 3D printed aluminum alloy materials yield on average The strength is up to 580 MPa, the ultimate strength exceeds 600 MPa, and the average elongation exceeds 8%.
The newly emerging high-strength aluminum alloy 3D printing materials focus on the application in the manufacture of high value-added parts for aerospace. For the field of automobile manufacturing, the cost of commonly used aluminum alloy materials is low, but currently metal 3D printing is still a high-cost technology, which seems to be the resistance to the application of aluminum alloy 3D printing technology in the mass production of automotive parts.
However, as can be seen from the EDAG's 3D printing projects for automotive parts carried out in the past few years, EDAG is committed to developing a disruptive new generation of vehicles and some high value-added automotive parts, such as EDAG and Bosch Germany The concept car Soulmate, its lightweight body is composed of 3D printed "skeleton structure" and a thin and light covering outer layer. The manufacturing method of the 3D printed "skeleton structure" is also the powder bed laser melting process.
EDAG's upcoming CustAlloy® 3D printed aluminum alloy material may be designed for the next generation of vehicles that are extremely disruptive in design.