Topic Review
Tube High-Pressure Shearing
Tube high-pressure shearing (t-HPS) is a deformation processing, in which a tubular sample is subjected to azimuthal shearing under a hydrostatic pressure. The shear plane is in parallel to the cylindrical surface of the tube, and the shear direction is in the azimuthal direction. 
  • 457
  • 25 Oct 2021
Topic Review
Chloride-Induced Corrosion of Carbon Steel in Cracked Concrete
Corrosion is an electrochemical reaction consisting of anodic and cathodic half-cell reactions. Micro-cell corrosion refers to the situation where active dissolution and the corresponding cathodic half-cell reaction occur in adjacent parts of the same metal. For a steel reinforcing bar in concrete, the surface of the corroding steel can act as a mixed electrode containing both anode and cathode regions connected by the bar itself. Macro-cell corrosion can also form on a single bar exposed to different environments within the concrete or where part of the bar extends outside the concrete. In both cases, the concrete pore solution functions as an electrolyte.
  • 452
  • 16 Jun 2022
Topic Review
Critical MIM + SH Processing Parameters
Metal injection molding (MIM) combined with the use of a space holder (SH) is a very attractive route for the fabrication of highly porous titanium and titanium alloy components for biomedical applications. This approach allows fine control of the morphology, architecture, and purity of very complex net-shaped components.
  • 445
  • 13 May 2022
Topic Review
Effect of Accelerating Methods on Gas Nitriding
Gas nitriding, as a surface modification technology to improve the wear resistance of workpiece surfaces, is widely used in wind turbine gears, pressure vessel gears, high-precision die casting abrasives, and other areas. However, the gas nitriding time is too long, reaching 40–60 h, which reduces the efficiency of nitriding and hinders the development of gas nitriding. Therefore, various accelerating methods are born accordingly. There are five common accelerating methods are summarized: process parameter optimization, surface mechanical nano-crystallization, surface-active catalysis, surface pre-oxidation, and surface laser treatment. 
  • 442
  • 13 Nov 2023
Topic Review
Stir Casting Routes for Metal Matrix Syntactic Foams
Metal matrix syntactic foams (MMSFs) are advanced lightweight materials constituted by a metallic matrix and a dispersion of hollow and/or porous fillers. Physical and mechanical properties can be fitted regarding matrix and filler properties and processing parameters. Their properties make them potential materials for sectors where density is a limiting parameter, such as transport, marine, defense, aerospace, and engineering applications. MMSFs are mainly manufactured by powder metallurgy, infiltration, and stir casting techniques. Stir casting techniques (SCTs) are low-cost and industrially scalable approaches. Critical limitations of SCTs are buoyancy of fillers, corrosion of processing equipment, premature solidification of molten metal during mixing, cracking of fillers, heterogeneous distribution, and limited incorporation of fillers. Efforts to overcome these limitations have led to the development of new techniques and to obtain MMSFs with improved properties.
  • 434
  • 19 Apr 2022
Topic Review
Laser Ultrasonic in a Smart Manufacturing Production Site
The advancement of laser ultrasonics has increased rapidly, providing applications for materials characterization as well as for industrial utilization, as a quality control device. The wide-ranging capabilities for high-temperature in-situ analysis of a variety of microstructural characteristics offers a multitude of possibilities for usage in R&D. One possibility to investigate in a contactless manner, in-situ, and at high temperatures is the laser ultrasonic (LUS) method. This measurement technique has been developed over the last decades for many fields of application and can be used in various different configurations. This method can be applied to a variety of analyses known from the conventional ultrasonic technique. In particular, defect detection is one of the most common applications, especially the detection of defects in terms of pores, voids, or adhesion defects, especially in castings or welds. However, such defect detections are also of great advantage in additive manufacturing. 
  • 433
  • 28 Feb 2023
Topic Review
Erosive Wear of Cermets
Solid-particle erosion occurs when discrete solid particles strike a surface. It differs from three-body abrasion primarily in the origin of forces between the particles and the wearing surface. In erosion, the extent of wear depends on the number and mass of individual particles striking the surface and on their impact velocity [8]. The difference of erosion from the abrasive wear lies in its fluid contribution to the mechanical action producing material removal. Solid-particle erosion is common in any system in which a gas stream carries abrasive particles. If loose abrasive particles are carried by a liquid, the wear is termed as slurry erosion.  WC-based hardmetals (cemented carbides) are employed widely as wear-resistant ceramic-metal composites for tools and wear parts. Raw materials supply, environmental concerns and some limitations of hardmetals have directed efforts toward development of alternative wear-resistant composites-cermets. Cermets consist primarily of ceramic particles such as titanium carbonitride (Ti(C,N)), titanium carbide (TiC), and chromium carbide (Cr3C2) bonded with alloys of Ni, Co or Fe. Cermets as resistant to solid particle erosion materials demonstrate their potential primarily in environmentally severe wear conditions – at elevated temperatures and corrosive environments.
  • 429
  • 10 Jan 2022
Topic Review
Grinding Media in Ball Mills for Mineral Processing
The ball mill is a rotating cylindrical vessel with grinding media inside, which is responsible for breaking the ore particles. Grinding media play an important role in the comminution of mineral ores in these mills.
  • 426
  • 24 Nov 2023
Topic Review
Lithium Production and Recovery Methods
The first step of hydrometallurgical treatment is leaching, which is an effective method capable of transferring over 99% of the present metals to the leach solutions. Extraction of metals after leaching can be conducted using various methods, with precipitation being the most commonly used. The precipitation of other metals can result in the co-precipitation of lithium, causing total lithium losses up to 30%. To prevent such losses, solvent extraction methods are used to selectively remove elements, such as Co, Ni, Al, and Mn. Solvent extraction (SX) is highly effective, reducing the losses to 3% per extraction stage and reducing overall lithium losses to 15%. After the refining, lithium is precipitated as lithium carbonate. High lithium carbonate solubility (1.5 g/L) and high liquid to solid leaching ratios require costly and avoidable operations to be implemented in order to enhance lithium concentration. Therefore, it is suggested that more studies should focus on multistage leaching with lower L/S ratios.
  • 422
  • 14 Jul 2023
Topic Review
Carbon Nanotubes-Based Nano Materials
High modulus of about 1 TPa, high thermal conductivity of over 3000 W/mK, very low coefficient of thermal expansion (CTE), high electrical conductivity, self-lubricating characteristics and low density have made carbon nanotubes (CNTs) one of the best reinforcing materials of nano composites for advanced structural, industrial, high strength and wear-prone applications. This is so because it has the capacity of improving the mechanical, tribological, electrical, thermal and physical properties of nanocomposites.
  • 413
  • 01 Mar 2023
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