New lightweight alloys for additive manufacturing a powder producers approach

Aluminum alloys represent an important product group for different engineering applications due to the specific characteristics of these materials. Due to the huge variety of potential alloying elements, resulting in very specific microstructures, aluminum alloys are often designed according to the needs of the application. Considering the use of powder-based processing routes, the inevitable oxide layer which acts as a sintering barrier makes the use of Al based powders challenging and puts limits to the available process routes. Powder Bed Fusion (PBF) methods offer an attractive alternative to overcome such obstacles, but for binder jetting processes the limitations on sinterability have to be kept in mind. Please click Additional Files below to see the full abstract

Metal additive manufacturing and powder metallurgy

Additive manufacturing is older than most people recognize. The state of the art Metal Additive industry of today was brought about by various technological advances in related fields such as laser technology and CAD/CAM systems. This presentation will offer a broad overview of the history of Metal Additive Manufacturing and provide an introduction into various processes utilizing metal powders. It will also explore uses of the technology and begin the conversation about where and when AM technologies appear to be useful. This dynamic field changes almost daily and new technologies or ideas are constantly evolving, but this presentation should provide a basic understanding

Microstructural Assessment of a Multiple-Intermetallic-Strengthened Aluminum Alloy Produced from Gas-Atomized Powder by Hot Extrusion and Friction Extrusion

An aluminum (Al) matrix with various transition metal (TM) additions is an effective alloying approach for developing high-specific-strength materials for use at elevated temperatures. Conventional fabrication processes such as casting or fusion-related methods are not capable of producing Al–TM alloys in bulk form. Solid phase processing techniques, such as extrusion, have been shown to maintain the microstructure of Al–TM alloys. In this study, extrusions are fabricated from gas-atomized aluminum powders (≈100–400 µm) that contain 12.4 wt % TM additives and an Al-based matrix reinforced by various Al–Fe–Cr–Ti intermetallic compounds (IMCs). Two different extrusion techniques, conventional hot extrusion and friction extrusion, are compared using fabricating rods. During extrusion, the strengthening IMC phases were extensively refined as a result of severe plastic deformation. Furthermore, the quasicrystal approximant IMC phase (70.4 wt % Al, 20.4 wt % Fe, 8.7 wt % Cr, 0.6 wt % Ti) observed in the powder precursor is replaced by new IMC phases such as Al3.2Fe and Al45Cr7-type IMCs. The Al3Ti-type IMC phase is partially dissolved into the Al matrix during extrusion. The combination of linear and rotational shear in the friction extrusion process caused severe deformation in the powders, which allowed for a higher extrusion ratio, eliminated linear voids, and resulted in higher ductility while maintaining strength comparable to that resulting from hot extrusion. Results from equilibrium thermodynamic calculations show that the strengthening IMC phases are stable at elevated temperatures (up to ≈ 600 °C), thus enhancing the high-temperature strength of the extrudates