Spark plasma sintering (SPS), a sintering method that uses the action of pulsed direct current and pressure, has received a lot of attention due to its capability of exerting control over the microstructure of the sintered material and flexibility in terms of the heating rate and heating mode. Historically, SPS was developed in search of ways to preserve a fine-grained structure of the sintered material while eliminating porosity and reaching a high relative density. These goals have, therefore, been pursued in the majority of studies on the behavior of materials during SPS. Recently, the potential of SPS for the fabrication of porous materials has been recognized. This article is the first review to focus on the achievements in this area. The major approaches to the formation of porous materials by SPS are described: partial densification of powders (under low pressures, in pressureless sintering processes or at low temperatures), sintering of hollow particles/spheres, sintering of porous particles, and sintering with removable space holders or pore formers. In the case of conductive materials processed by SPS using the first approach, the formation of inter-particle contacts may be associated with local melting and non-conventional mechanisms of mass transfer. Studies of the morphology and microstructure of the inter-particle contacts as well as modeling of the processes occurring at the inter-particle contacts help gain insights into the physics of the initial stage of SPS. For pre-consolidated specimens, an SPS device can be used as a furnace to heat the materials at a high rate, which can also be beneficial for controlling the formation of porous structures. In sintering with space holders, SPS processing allows controlling the structure of the pore walls. In this article, using the literature data and our own research results, we have discussed the formation and structure of porous metals, intermetallics, ceramics, and carbon materials obtained by SPS.

High-energy ball milling (HEBM) of powders is a complex process involving mixing, morphology changes, generation and evolution of defects of the crystalline lattice, and formation of new phases. This review is dedicated to the memory of our colleague, Prof. Michail A. Korchagin (1946–2021), and aims to highlight his works on the synthesis of materials by self-propagating high-temperature synthesis (SHS) and thermal explosion (TE) in HEBM mixtures as important contributions to the development of powder technology. We review results obtained by our group, including those obtained in collaboration with other researchers. We show the applicability of the HEBM mixtures for the synthesis of powder products and the fabrication of bulk materials and coatings. HEBM influences the parameters of synthesis as well as the structure, phase composition, phase distribution (in composites), and grain size of the products. The microstructural features of the products of synthesis conducted using the HEBM precursors are dramatically different from those of the products formed from non-milled mixtures. HEBM powders are also suitable as feedstock materials for depositing coatings by thermal spraying. The emerging applications of HEBM powders and future research directions in this area are discussed.