Encapsulation of bimodal metal powders as a tool to manage the properties of hierarchically organized structures

Encapsulation of bimodal powders based on nano- and microparticles of 316L, Ti-6Al-4V, Ti-Al and 90W-6Ni-4Fe alloys by organic ligands result in the formation of a lyophilic layer on the particle surface, reduction of powder agglomeration and spontaneous formation of hierarchically organized close-packed structures. The behavior of encapsulated hierarchical micro/nanostructures based on bimodal alloy powders when sintering was investigated. Encapsulation of 316L, Ti-6Al-4V and 90W-6Ni-4Fe alloys powders leads to an increase in the initial density of compacted powders and an increase in the relative density of sintered samples compared to untreated powders. On the contrary, encapsulation of Ti-Al alloy powder tends to reduce both the initial density and the density of the samples sintered at 1200°C. The sintering behavior of samples is influenced by both the chemical structure of the encapsulating agent and the chemical composition of the alloy particles.