The technology of sevenfold increase in the strength of titanium and steel products is presented
Physicists from NUST MISIS, together with their French colleagues, have proposed a method to increase the strength of titanium and stainless steel products sevenfold. According to the developers, for the first time in the world, they managed to combine two technologies for processing metals that were considered incompatible, and thanks to this, they achieved a sharp improvement in the properties of materials. Research results published in the journal Surface and Coatings Technology …
In many branches of modern industry, the production of critical products designed for high loads requires improved properties from metals – increased density and strength, as well as plasticity and corrosion resistance. For such processing today, according to experts, the method of hot isostatic pressing (HIP) is widely used.
However, compaction by the HIP method did not previously give serious results when processing materials obtained by the popular technology of cold gas-dynamic spraying. This technology, according to scientists, today is becoming one of the key technologies for aircraft and automobile manufacturing, electrical engineering and medicine, as it allows “growing” unique products with a given structure.
For the first time in the world, NUST MISIS scientists have succeeded in finding the parameters of metal processing that make it possible to combine the effect of both methods, and thereby dramatically increase the useful characteristics of the materials obtained.
“We applied HIP for materials that were not previously recommended for such processing, as they have a loose surface due to the presence of open pores. By applying a thin layer of the same metal to a loose product in a special way, we have obtained a kind of hermetically sealed capsule, which makes it possible to successfully use HIP. Thanks to this treatment, the porosity more than halved, the compressive strength increased by 25 percent, and most importantly, the tensile strength increased many times over, ” said Vladimir Cheverikin, head of the program “Additive Technologies for the iPhD Manufacturing Industry” of NUST MISIS.
In particular, the tensile strength of stainless steel and pure titanium has increased approximately sevenfold. Most impressive results were obtained with titanium and aluminum alloy Ti6AL4Vwhose tensile strength has increased 28 times… The improvement in mechanical properties is provided by diffusion of the material and changes in its microstructure, the scientists explained.
The study was carried out in collaboration with scientists from the University of Lyon (France). Based on the results obtained, the research team plans to develop new materials for the medical industry.