Microstructure Evolution News Today

The microstructure and high-temperature creep mechanisms of Ni-based Hastelloy C276 superalloy fabricated using wire and arc-based directed energy deposition were investigated systematically and innovatively. The microstructural investigation revealed that the as-fabricated samples comprise γ-Ni matrix and topologically close-packed (TCP) P phase precipitates. The γ matrix subgrains and grains are spread over multiple highly textured columnar dendrites, with a majority of γ <001> crysta...

This article provides an overview of carbon steel and the impact of the carbon content on its strength and ductility.

Over the course of the 2022–2023 academic year, nine faculty members across the UMass Amherst campus have been named the recipients of National Science Foundation (NSF) CAREER awards.The Faculty Early Career Development (CAREER) Program is a foundati

In this paper, a Fe, Cr-rich multiphase Ni3Al-based alloy is joined through transient liquid phase bonding (TLP) technique. Different from typical γ+γ′ dual phase Ni3Al-based alloys, the joint can be divided into three distinct zones: isothermal solidification zone (ISZ), gamma prime zone (GPZ) and diffusion affected zone (DAZ). Interestingly, the massive fine grains with γ+γ′ dual phase are observed inside the ISZ, and the GPZ consists of blocky γ′ phase. The precipitation of Cr-rich...

A functionally graded AlxCoCrFeNi high entropy alloy with a variation in Al concentration along the building direction was in-situ produced using a hybrid powder-bed wire-based direct energy deposition process. A continuous transition from a single FCC structure to a major BCC+minor FCC dual-phase structure was achieved, benefiting from the remelting and reheating process during the deposition. In the FCC→BCC transition zone, the dendritic core region is identified as an FCC matrix decorated b...

The interfacial zone formed in the manufacturing process of bimetal or laminated metal composites owes complicated microstructures and properties. This special feature greatly affects the fracture toughness and fatigue strength of metal composites. The crack growth behaviours, from a weak layer (AH36 carbon steel) to a strong layer (2205 duplex stainless steel), at the interfacial zone of a hot-rolled bimetal composite (2205/AH36 BC) were investigated. To clarify the potential factors altering t...

The construction of heavy polar icebreakers is usually done with special hull steels, which require comprehensive properties such as good low-temperature toughness, high strength, and superior fatigue resistance. Reasonable and satisfactory heat treatments should be investigated and applied to acquire the required high strength and superior low-temperature toughness, since this is deemed an effective approach to ameliorate the combined properties of high-strength hull steels. Regarding this, the...

Laminated/bimetal composites can offer the advantage of combining constituent metals, but their heterogeneous microstructures exhibit different mechanical properties during subsequent remanufacturing process than those of the homogeneous counterparts. This study investigated the tensile properties, microstructural evolution and deformation behaviours of a new explosive welded TA1/5083 composite sheet using the in-situ characterisation. It is found that a wavy transition zone forms in the composi...

Novel G115 martensitic steel (G115 steel) with excellent creep properties, oxidation resistance and low manufacturing cost, has been widely used for ultra-super critical (USC) power plants. Microstructural evolutions were characterized using multiple methods, and their effects on mechanical properties of G115 steel after secondary normalizing process at different temperature (1000 °C, 1050 °C and 1100 °C) were also investigated. The results show that the average width of martensitic lath decr...

In a recent study published in the journal Materials, researchers from China developed a permeable brick by utilizing industrial solid waste.