A Review on Metallic Alloys Fabrication Using Elemental Powder Blends by Laser Powder Directed Energy Deposition Process

The laser powder directed energy deposition process is a metal additive manufacturing technique, which can fabricate metal parts with high geometric and material flexibility. The unique feature of in-situ powder feeding makes it possible to customize the elemental composition using elemental powder mixture during the fabrication process. Thus, it can be potentially applied to synthesize industrial alloys with low cost, modify alloys with different powder mixtures, and design novel alloys with location-dependent properties using elemental powder blends as feedstocks. This paper provides an overview of using a laser powder directed energy deposition method to fabricate various types of alloys by feeding elemental powder blends. At first, the advantage of laser powder directed energy deposition in manufacturing metal alloys is described in detail. Then, the state-of-the-art research and development in alloys fabricated by laser powder directed energy deposition through a mix of elemental powders in multiple categories is reviewed. Finally, critical technical challenges, mainly in composition control are discussed for future development.

Investigation of Ti-6Al-4V Alloy In Situ Manufactured Using Selective Laser Melting from Elemental Powder Mixture

This paper presents the results of the study of Selective Laser Melting (SLM) process for the in-situ synthesis of Ti-6Al-4V alloy from elemental powder mixture. Elemental spherical powders of Ti, Al and V were used to prepare a powder mixture, and then bulk specimens were produced by SLM using different process parameters. The effects of SLM process parameters on samples’ relative density, their chemical composition, the formed microstructure and microhardness before and after heat treatment have been studied. It was shown that volume energy density during the SLM process significantly effects the microstructure and microhardness of Ti-6Al-4V obtained from elemental powders. The difference in microstructure morphology and microhardness remains after heat treatment.

Effect of Selective Laser Melting Process Parameters and Heat Treatment on Microstructure and Properties of Titanium Alloys Produced from Elemental Powders

This work investigates the Selective Laser Melting (SLM) process for the in-situ synthesis of Ti-5Al and Ti-6Al-4V alloys using elemental powder mixture. Elemental spherical powders were used to prepare a powder mixture and then samples were produced by SLM using different volume energy density. The effects of volume energy density during SLM on samples’ relative density, chemical composition, microstructure and microhardness before and after heat treatment have been studied. It was shown that volume energy density during the SLM process significantly effects the density, microstructure of Ti-5Al and Ti-6Al-4V alloys, as well as, the microhardness of Ti-6Al-4V obtained from elemental powders.

Novel Ti2CuCx and Ti3Cu2Cx Carbides Obtained by Sintering of Products of Mechanochemical Synthesis of Ti, Cu and Carbon Nanotubes

Mechanical alloying of the elemental powder mixture of titanium and copper (particle size of both powdersis about 40 μm, purity is not less than 99.6% wt. %) was performed in a high energy planetary ball mill to obtainTi:Cu (2:1 and 3:1) compositions. An addition of 1 vol. % of multiwalled carbon nanotubes (MWCNT, averagediameter 10-20 nm) into Ti-Cu charge results in a formation of nanoscaled Ti2CuCx and Ti3Cu2Cx carbides(containing 0.5 and 4.2 at.% of carbon and 30.8 and 37.5 at.% of copper, respectively). These carbides havesynthesized for the first time. Nature of interaction of the charge components at processing in a ball mill hasstudied on test samples using a complex of X-ray techniques. These techniques include a full-profile analysis forthe primary processing of diffractograms obtained with DRON-3M apparatus; qualitative and quantitative phaseanalysis for determining the phase composition of the products of synthesis; X-ray structural analysis to verifyand refine the structural models; Williamson-Hall method for determining the grain sizes. The Vickers hardnessof compacted (by sintering) samples with 20.1 and 27.3 at. % Cu varies substantially within (6.9-7.1) GPa. Thus,the average microhardness of synthesized materials is 7 times higher than that of pure titanium microhardness.