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Source: Gaishi Automobile
The Antarctic Bear learned that researchers at the Oak Ridge National Laboratory (ORNL) of the United States Department of Energy found a mechanism called “load shuffling” in 3D printing alloys, which can design lightweight materials with better performance for vehicles. Related papers have been published in the journal Acta Materialia.
One way to improve vehicle energy efficiency is to use aluminum based materials to make the vehicle lighter. When one of ORNL’s ACMZ (aluminum, copper, manganese, and zirconium) alloys undergoes deformation under sustained mechanical stress at high temperatures, researchers monitored the material.
By using neutron diffraction, the researchers studied the atomic structure of the material, and observed that the overall stress was absorbed by one part of the alloy, but transferred to another part during deformation. This round robin restructuring has prevented the strengthening of certain areas.
Researchers such as Michi stated that although the volume fraction is as high as nearly 10%, the main strengthening phase in the alloy θ- Al2Cu still does not provide load transfer reinforcement during creep deformation. On the contrary, the evolution of lattice strain proposes a new mechanism called “load restructuring”, in which the initial load is transferred from the precipitate free region along the grain boundary, while most θ- Al2Cu particles are located inside precipitation strengthened grains.
Despite the lack of load transfer strengthening, the AM Al Cu Mn Zr alloy manufactured still has higher creep resistance at 300 ° C compared to cast alloys with similar compositions. The proposed load restructuring mechanism explains the lack of L12-Al3Zr strengthening observed at 300 ° C and helps identify several strategies to improve the high-temperature mechanical response of AM aluminum alloys.
Amit Shyam, a researcher at ORNL, said, “Neutrons provide an opportunity to study the metallurgical phenomena of multiphase structured materials. We have made new progress in our research on high-temperature materials, so we will be able to design improved aluminum alloys suitable for extreme conditions
