Nowadays, the concept of high entropy alloys (HEAs) has expanded the limits of metallurgy and high-quality metallurgical HEAs ingots have already been successfully obtained on an industrial scale. High Chromium Cast Irons (HCCI) and Multi-Component Cast Irons (MCCI) are known to be a useful material for applications when abrasion resistance is required. Inspired by the concepts of high-entropy alloys, a base HCCI was modified, by adding other carbide-forming elements, at concentrations higher than what is currently used, in order to develop a new class of white cast iron, High Entropy White Cast Iron (HEWCI). The characterization of carbides precipitated during the HEWCI solidification was performed by scanning electron microscopy, energy dispersive spectroscopy, electron backscattered diffraction (SEM/EDS/EBSD) and X-ray diffraction (XRD). With the characterization techniques employed, the as-cast microstructure obtained of HEWCI is composed of approximately 50% of austenite matrix and 50% of different types of carbides, MC, M7C3 and M2C carbides.

White cast irons (WCI) are widely used in industries requiring high wear resistance due to their microstructure consisting of hard carbides dispersed within a metallic matrix. This study focuses on developing wear-resistant multi-component hypereutectic high chromium cast irons, merging concepts of high entropy alloys with the conventional metallurgy of white cast irons, specifically exploring the influence of carbide-forming elements such as V, Mo, and Ni on solidification behavior, microstructure, and wear performance. The research investigates the solidification process of the alloys using Computer-Aided Cooling Curve Analysis (CA-CCA) and characterizes the microstructures through X-ray diffraction (XRD) and scanning electron microscopy (SEM). The wear behavior of the developed alloys is evaluated through reciprocating sliding wear tests, revealing the impact of varying chemical compositions on wear resistance. The results demonstrate that high-entropy white cast iron (HEWCI), particularly those enriched with carbide-forming elements, exhibit superior abrasion resistance compared to conventional high-chromium cast irons. The alloy with 2 Mo and 4 V content showed the best performance, presenting the lowest wear rate (61.5% lower than HCCI alloy) and CoF (values ranging from 0.20 to 0.22) due to the highest concentration of V carbides.

High Chromium Cast Iron (HCCI) has demonstrated its effectiveness as a potential material for applications in severe environments due to its remarkable wear resistance attributed to the volumetric fraction of carbides in the microstructure. This study investigates a novel high-alloyed composition of white cast iron named High Entropy White Cast Iron (HEWCI), which merges the concepts of HCCI and high entropy alloys. Specifically designed chemical compositions incorporating Vanadium (V), Molybdenum (Mo), and Nickel (Ni) were employed to enhance its wear resistance properties. The solidification path, microstructural characterization, and wear responses of HEWCI were evaluated. XRD and SEM techniques were carried out for characterization purposes. Linearly reciprocating ball-on-flat sliding wear tests were conducted using a high-frequency reciprocation rig (HFRR) tribometer, assessing wear volume, linear wear rate, specific wear rate (κ), and coefficient of friction (COF). The results revealed microstructural refinement and precipitation of new carbides through V, Ni, and Mo additions. This approach demonstrates that adding carbide-forming elements and refining the microstructure are promising strategies for enhancing wear performance in HEWCI alloys.

Ductile iron is typically used in as-cast conditions. However, a typical heat treatment applied to ductile iron is austempering, which allows for increased tensile strength with good levels of elongation and toughness. The traditional means of austempering involves molten salt baths, but these baths have environmental and operational restrictions. Laboratory-level studies have found the feasibility of using heated air for cooling and holding during austempering. Due to the lower cooling severity of heated air, it is necessary to increase the austemperability of ductile iron. Elements that contribute to austemperability are manganese, copper, molybdenum, and nickel. This study used numerical, thermodynamics, and kinetics simulation to develop a suitable ductile iron alloy for obtaining ADI in a standard ASTM test specimen using heated air for cooling. According to the numerical simulation results, the average cooling rate between 900°C and 500°C in the critical region for air velocities of 5 m/s and 10 m/s at a temperature of 280°C ranged from 75°C/min to 82°C/min. Through thermodynamic and kinetic simulation, nickel has the most significant capacity to alter the austemperability of ductile iron. Based on these results, six ductile iron alloys with nickel contents ranging from 0.2 to 2% were developed. The experimental cooling rate is approximately 70°C/min, with the 3.41C, 2.72Si, 1.01Cu, 0.31Mn, 0.18Mo, and 1.13Ni alloy suitable for obtaining ADI.