In the quest for excellent light-structural materials that can withstand mechanical extremes for advanced applications, design and control of microstructures beyond current material design strategies have become paramount. Herein, we design a coherent shell at incoherent precipitates in the 2195 aluminum alloy with multi-step metastable phase transitions. A high local strain rate via a neoteric deformation-driven metallurgy method facilitated the diffusion of Li. The original T₁ (Al₂CuLi) phases were transformed into coherent-shell (Li-rich) irregular-coated incoherent-core (Al₂Cu) precipitates. The ultimate tensile strength and elongation reached 620 ± 18 MPa and 22.3 ± 2.2%, exhibiting excellent strength–ductility synergy. Grain boundaries, dislocation, solid solution atoms, and precipitates all contributed to the yield strength of the materials, among which precipitates occupied a dominant position, contributing approximately 56.07%. A new “incoherent–coherent interact” strain-hardening mechanism was also clarified, which was believed to be promoted in other heat-treatable alloy systems, especially with multi-step metastable phase transitions.

Analysis of the current state of additive welding technologies for manufacturing volume metallic products (review)

Using of welding technologies to produce metal volume objects allows considerable lowering of their manufacturing cost at simultaneous increase in productivity, compared to SLS-and SLM-processes. The most perspective welding technology of additive manufacturing of three-dimensional objects is plasma-arc technology with application of wires or powders. It allows creating at comparatively low heat input quality volumetric products with wall thickness from 3 to 50 mm from alloys based on Fe, Ni, Co, Cu, Ti, Al, as well as composite materials, containing refractory components.

In order to ensure high wear resistance of parts and tools, operating at significant dynamic loads in the extreme conditions, the layers different in their function purpose obtained using surfacing methods are widely used. In such surfacing compositions, the powders of high-melting compounds characterized by high hardness and strength, are used as a wear resistant component, for example, alloys of tungsten carbide WC + W₂C (cast tungsten carbide), and as binder matrix the plastic and metal alloys are used.The great interest is the development of methods allowing producing powders of cast tungsten carbide and other high-melting-point materials of uniform composition, characterized by a high sphericity of the particles and having higher physical-mechanical properties. The spherical tungsten carbide was produced by plasma atomization of rotating billet. The universal installation for production of super-hard spherical tungsten carbide and other high-melting-point compounds by plasma atomization of rotating billets was designed for industrial application. The results showed that the application of the technology of plasma rotary atomization of rotation billet to obtain granules of powders of high-melting-point materials was promising, in particular tungsten carbide with sphericity over 90%, microhardness HV0.1 more than 3000 kg / mm² characterized by high flow ability more than 7.5 s/ 50 g. Due to the use of new materials and innovative design and technological solutions the high reliability, maximum interval of technical service, high resource of operating units and executing mechanism of the equipment were ensured. Due to the use of new high-power plasma system with power supply source with high efficiency coefficient and improved dynamic characteristics, the system of preliminary heating of billets, innovative gas systems, high performance vacuum system, the developed universal system for the production of granules of powders of high-melting-point material were also applicable for the manufacture of spherical powders of metals and alloys, including highly active, and provided lower costs of products (powder) with an increased productivity, economic efficiency of the atomization process and reduced the impact of atomization process on the environment.