Liquid phase sintering (LPS) is a process for forming high performance, multiple-phase components from powders. It involves sintering under conditions where solid grains coexist with a wetting liquid. Many variants of LPS are applied to a wide range of engineering materials. Example applications for this technology are found in automobile engine connecting rods and high-speed metal cutting inserts. Scientific advances in understanding LPS began in the 1950s. The resulting quantitative process models are now embedded in computer simulations to enable predictions of the sintered component dimensions, microstructure, and properties. However, there are remaining areas in need of research attention. This LPS review, based on over 2,500 publications, outlines what happens when mixed powders are heated to the LPS temperature, with a focus on the densification and microstructure evolution events.

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Review: liquid phase sintering

Cemented carbides cover a wide range of applications in many relevant industries, i.e. as cutting tools (turning, milling, drilling) for machining of metal components in the automotive and/or aerospace industry, as components of drill bits or road headers in the rock tools and mining area or as wear parts in wire drawing dies or punch tools. In this review selected cemented carbide and cermet microstructures are presented. The focus is on microstructures, both those that are already established in the cemented carbide industry and those which have drawn scientific attention due to new potential applications. Cemented carbides are here divided in four groups based on microstructure and chemistry: WC morphology and chemistry, cubic carbide containing cemented carbide and cermets, functionally graded cemented carbides, and binder design of cemented carbides. Furthermore, this review covers some historical background that motivated the microstructure design as well as the status of each class of materials nowadays. The paper aims at categorising cemented carbides in a structured way and to serve as an introduction to cemented carbide microstructures for engineers, researchers and scientists.

Cemented carbide microstructures: a review

Processing-structure-property aspects of particulate- and whisker-reinforced titanium matrix composites

In the past 14 years, as a branch of high-entropy alloy (HEA) materials, HEA films and coatings have exhibited the attractive and unique properties, relative to the conventional film and coating ma...

https://www.tandfonline.com/doi/pdf/10.1080/21663831.2018.1434248

Microstructures and properties of high-entropy alloy films and coatings: a review

Precipitation of Al3(Sc,Zr) particles in an Al-Zn-Mg-Cu-Sc-Zr alloy during conventional solution heat treatment and its effect on tensile properties

A study has been made of the shape development of WC crystals in cemented carbides during liquid phase sintering. The relative influence of shape relaxation and carbide crystal growth processes on the shape is discussed. An effect of titanium additions on the shape of WC crystals in WC–Ni cemented carbides was observed. A shape parameter referred to as shape equiaxiality has been defined and calculated theoretically for various triangular prisms. The observed change of shape equiaxiality with titanium concentration in the binder phase of WC–Ni cemented carbides is discussed in terms of titanium segregation at the interphase boundary.

The shape of WC crystals in cemented carbides

A titanium matrix composite having eutectically formed titanium alloy reinforcement containing at least two of the elements of silicon, aluminum, zirconium, manganese, chromium, molybdenum, carbon, iron, boron, cobalt, nickel, germanium and copper.

Titanium matrix composites

Preface. Introduction. 1: General Overviews. Opportunities and approaches for doubling the structural efficiency of metallic materials D.B. Miracle. The challenge for materials design: integrating modeling and computation C.S. Hartley. The main tendencies in elaboration of materials with high specific strength S. Firstov. 2: Amorphous, Nanocrystalline and Quasicrystalline Materials. Nanostructured materials produced by severe plastic deformation H.P. Stuwe. Development of nanostructured and nanoparticle dispersion-reinforced metallic systems P.R. Subramanian, et al. Nanostructured and nanocomposite light metal-based compounds for hydrogen storage R.A. Varin, et al. Strength and ductility of nanostructured SPD materials R.Z. Valiev. Consolidation of Cu and amorphous Zr-based powders by severe plastic deformation K.T. Hartwig, et al. Structure and properties of carbon-based nanocomposite films G. Radnoczi, et al. Nanocrystallization in iron alloys induced by friction treatment and nitrogen diffusion A. Yurkova, et al. Influence of scandium on amorphization of aluminum alloys A. Slipenyuk, et al. Structure peculiarities of Al63Cu25Fe12 ingots with a quasicrystalline component M. Yefinov, et al. Consolidation of Al-Cu-Fe powders with quasicrystalline component by using high quasihydrostatic pressures O. Bykov, et al. 3: Advanced Aluminum and Magnesium Alloys. High strength aluminum alloys for cryogenic applications O.N. Senkov, et al. Effect of Fe and Si on structure and mechanical properties of complex Al-Zn-Mg-Cu alloys produced by P/M casting techniques Yu. Milman, et al. Study of a zirconium modified 2014 aluminumalloy: analysis of the best warm forming conditions P. Cavaliere. Study of fatigue resistance properties of a zirconium modified 2014 aluminum alloy P. Cavaliere. High strain rate superplastic behavior of Al-Li-Mg-Cu-Sc alloy subjected to severe plastic deformation M.R. Shagiev, et al. Microstructure and mechanical properties od Al-Al4C3 materials M. Besterci, L'. Parilak. Creep behavior and strength of magnesium-based composites V. Sklenicka, et al. 4: Advanced Titanium Alloys and Composites. Multicomponent Ti-Si-based systems M. Bulanova, et al. Effect of Zr on structure and mechanical behavior of Ti-Al-Si alloys I. Gornaya, et al. High-temperature fatigue crack growth resistance of thermo-mechanically and heat treated cast Ti-Si-Al-Zr composites B. Vasyliv, et al. Structure and fracture features of Ti-Si- and Ti-B-based in situ composites O.D. Vasylyev, M.D. Bega. Effect of thermomechanical treatment on structure and properties of titanium-boride eutectic alloys T. Velikanova, et al. New high-strength weldable titanium alloy T110 V.N. Samkov, et al. Features of application of high-strength materials for units of the landing gear of aircrafts 'AN' A.G. Molyar, V.A. Trofimov. 5: Advanced Refractory Alloys. Structures and properties of the refractory silicides Ti5Si3 and TiSi2 and Ti-Si-(Al) eutectic alloys G. Frommeyer, R. Rosenkranz. Refractory metal/silicide multiphase systems for high temperature structural applications M.G. Mendiratta, et al. Microstructural effects and kinetics of high temperature oxidation in Nb-Si base alloys E.S.K. Menon, et al. Development of ductile Cr-Re alloys for high temperature application

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Metallic Materials with High Structural Efficiency

The dependences of fracture toughness and crack propagation on the shape equiaxiality of WC crystals are studied on WC–Ni cemented carbides with small addition of TiC. The fracture toughness K 1C linearly correlates to mean linear path in binder phase regardless of the shape and contiguity of WC crystals as well as despite of the fracture path change in studied WC–Ni cemented carbides. It is experimentally shown that the fracture toughness K 1C does not correlate versus contiguity of carbide crystals on WC–Ni cemented carbides when shape of WC crystals is changed. The relative amount of trans-crystalline fracture through the carbide crystals and the total area of fracture through the carbide phase increase, whereas, the relative amount of inter-crystalline fracture along carbide–carbide boundaries decrease on WC–Ni cemented carbides with flatter WC crystals and lower values of contiguity of WC crystals.

Fracture of WC–Ni cemented carbides with different shape of WC crystals

Nitride coatings with high hardness (600–650 GPa) are produced from a high-entropy multicomponent single-phase alloy containing five nitride-forming elements by vacuum arc deposition with application of pulsed implantation These high values of hardness are characteristic of metals in the equiatomic alloy only in nanostructured state The mechanical properties of the coatings annealed in the temperature range up to 1200 °C are studied It is established that the coatings are solid solutions of high-entropy nitride with fcc lattice The vacuum coatings inherit the same type of crystal lattice as that of the target (bcc) The crystal lattice of high-entropy vacuum coatings is formed through the mechanism revealed in the cast alloys The parameter of this lattice is close to that calculated by Vegard’s rule

S.A. Firstov

Papers

The shape of WC crystals in cemented carbides

Titanium matrix composites

Metallic Materials with High Structural Efficiency

Fracture of WC–Ni cemented carbides with different shape of WC crystals

Thermal Stability of Superhard Nitride Coatings from High-Entropy Multicomponent Ti–V–Zr–Nb–Hf Alloy