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The present study is a first step of a project to obtain thermo-mechanically processed fine-grained increased Mn content TRIP steels with large fractions of retained austenite. Two 0.17C-3Mn-1.6Al-0.2Si-0.2Mo steels with and without Nb microaddition were produced in a vacuum induction furnace. The influence of Nb microaddition on a macrostructure, a grain size and hot-working behavior were examined. The steels are characterized by a slight macrosegregation of Al in the as-cast state, minimized for a Nb-microalloyed steel. After hot forging refined bainitic-martensitic structures with large fractions of γ phase obtained. The steel microalloyed with Nb has finer granules of retained austenite at comparable fractions of this phase. The force-energetic parameters of hot-working were determined in an uniaxial hot-compression test at temperatures of 1150 and 950°C and strain rates from 0.1 to 10s-1. The Gleeble 3800 thermomechanical simulator was used. The hot-working behaviour of the investigated steels is challenging because of higher flow stresses and εmaxstrains compared to conventional TRIP steels with lower Mn contents.

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The aim of the paper was to investigate thermal stability, crystallization and magnetic properties of Fe-Cobased metallic glasses (MGs 4 . Thermal properties (liquidus T l and melting T m temperatures) of the pre-alloyed ingots upon heating and cooling were analyzed by DTA at a heating/cooling rate of 0.33 K s -1 under the purified argon atmosphere. The structure of the ribbons was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM) method. Kinetics of the crystallization process was examined by applying differential scanning calorimetry (DSC) method, and experiments performed in thermal analysis involve heating at a constant rates b = 0.17, 0.33 and 0.5 K s -1 . Additionally, the conventional crystallization temperature T x was determined from the normalized isochronal resistivity curves a(T) with heating rate 0.0083 K s -1 . a is the temperature coefficient of resistance and a = q

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Magnesium-based materials are interesting alternatives for medical implants, as they have promising mechanical and biological properties. Thanks to them, it is possible to create biodegradable materials for medical application, which would reduce both costs and time of treatment. Magnesium as the sole material, however, it is not enough to support this function. It is important to determine proper alloying elements and methods. A viable method for creating such alloys is mechanical alloying, which can be used to design the structure and properties for proper roles. Mechanical alloying is highly influenced by the milling time of the alloy, as the time of the process affects many properties of the milled powders. X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS) were carried out to study the powder morphology and chemical composition of Mg65Zn30Ca4Gd1 powders. Moreover, the powder size was assessed by granulometric method and the Vickers hardness test was used for microhardness testing. The samples were milled for 6 min, 13, 20, 30, 40, and 70 h. The hardness correlated with the particle size of the samples. After 30 h of milling time, the average value of hardness was equal to 168 HV and it was lower after 13 (333 HV), 20 (273 HV), 40 (329 HV), and 70 (314 HV) h. The powder particles average size increased after 13 (31 μm) h of milling time, up to 30 (45–49 μm) hours, and then sharply decreased after 40 (28 μm) and 70 (12 μm) h.