Production of Rounded Reactive Composite Ti/Al Powders for Selective Laser Melting by High-Energy Ball Milling

Abstract

The effect of different regimes of high-energy ball milling (HEBM) on the morphology of reactive Ti-Al powders was studied. It is shown that a ''soft'' regime of mechanical treatment can be readily used to prepare spheroidal reactive Ti-Al powders with the flow ability suitable for selective laser melting applications. Size distribution of milled powders was found to depend on the diameter of milling balls. Milled powders showed good flow ability of 61.7 and 81.25 s for 2-mm and 6-mm balls, respectively. Combustion reaction in the compacts prepared from milled powders got started at temperatures close to the melting point of Al, and due to the thermal effect of reaction, the temperature jump made a value of about 500°C. The combustion product-Ti-TiAl 3 composite-can be recommended for use as a high-temperature structural material.

Energy-Intensive Materials with Mechanically Activated Components

“…As a rule, mechanical activation (MA) leads to an increase in the burning rate in both low-and high-calorie systems. An increase in the burning rate after mechanical activation was observed in the Ti-C and Ni-Al systems [49] by four and thirty times, respectively. In both cases, melting of the metal reagents occurs.…”

TiAl-Based Materials by In Situ Selective Laser Melting of Ti/Al Reactive Composites

“…Ti (LLC "OCHV", purity 99%, particle size <45 µm) and Al (LLC "OCHV", purity 98.6%, particle size <10 µm) in stoichiometric ration were treated for 60 min and yielded the rounded Ti/Al powders with a size of 60-100 µm (Figure 1). More details on the high-energy ball milling protocol can be found elsewhere [21]. The as-formed composite powders were used as a feedstock for selective laser printing in SLM 280 HL installation (SLM Solutions Co. Lübeck, Germany).…”

Mechanical activation of metallic powders and reactivity of activated nanocomposites: a molecular dynamics approach

“…As an example, the combination of mechanical activation and reactive sintering leads to the formation of nanostructured intermetallics [4], and nanostructured High Entropy Alloys [5]. Nanocomposites prepared by mechanical milling are also used in additive manufacturing [6,7], where attention is also paid to particle size and shape. Characterizing the reactive properties of activated powders is important to design reactive material with tailored reactivity, and to choose the most adequate parameters for the elaboration process (e.g., milling speed).…”