According to foreign media reports, researchers from the Northwest National Laboratory of Anding Yang (PNNL) in the United States have demonstrated advanced manufacturing technology and directly made nanostructured aluminum rods and tubes by using high-performance aluminum alloy powder. The research group adopted a new solid-state processing method, which reduced several steps of traditional aluminum alloy powder extrusion processing, and significantly improved the ductility of products, that is, the tensile interval before fracture. This is good news for industries like automobiles. For a long time, high-performance aluminum alloy made of powder has been used in aerospace industry to manufacture lightweight components. But for the automotive industry, the cost of using these alloys is too high.
New technology of aluminum profile high performance aluminum alloy
The traditional aluminum alloy powder extrusion process has high energy consumption and complex process, which requires multiple steps for mass consumption data. First of all, the loose powder must be put into the tank and then vacuumed. This is called degassing. Then seal the tank, hot press, preheat and put it into the extruder. After extrusion, the tank body is removed or "emptied" to expose the extruded part composed of consolidated powder. In this study, the team removed many steps and used shear assisted processing and extrusion technology (shape) to directly extrude nanostructured aluminum rods from the powder in one step. The powder is poured into an open container, and then the rotating extrusion die is pressed into the powder to generate heat on the interface between the powder and the mold. It is easy to extrude after softening, and does not require canning, degassing, hot pressing, preheating and decanting. The al-12.4tm aluminum alloy powder in this case was provided by SCM metal products, a subsidiary of kemela international data company.
Scott Whalen, a PNNL data scientist, conducted the study. "This is the first published example of this type, using a single-step process such as shape to solidify aluminum alloy powder into nanostructured extrusions," he said. Reducing the processing steps and heating process will greatly reduce the consumption time, reduce the cost and the energy absorbed inside the products, and help the automobile manufacturers to consume cheaper, lighter and more fuel-efficient passenger cars. "
In addition to providing al-12.4tm powder, SCM metalwork also stopped mechanical testing to verify the properties of the extrusion data. Currently, PNNL and SCM metalwork are working with DOE's office of technology transformation to develop projects to expand the processing range and complete larger diameter extrusion.
Traditional high performance aluminum alloys usually have high strength but poor ductility. However, the research team found that the ductility of the extruded aluminum alloy with shape technology was significantly improved, which was two to three times of that of conventional extrusion products, and the strength was equivalent. To understand why, the researchers used transmission electron microscopy to examine the microstructure of the powder and extrusion data. The results show that the shape technology can refine the micro strengthening particles of non aluminum materials, reduce their size to nano scale, and evenly distribute on the aluminum matrix, so as to improve the ductility.