Sta 449 f1

DSC analysis was performed using a Netzsch STA-449-F1 differential scanning calorimeter (Netzsch, Germany). The measurement was conducted under N₂ atmosphere. The sample was heated from 25 °C to 235 °C at a rate of 10 °C/min and held at 235 °C for 10 min to eliminate the sample’s thermal history. Subsequently, the temperature was decreased to 25 °C at a rate of 10 °C/min. Afterward, the second heating program was performed, where the temperature was still increased from 25 °C to 235 °C at a rate of 10 °C/min but without any holding time, and decreased from 235 °C to 25 °C at a rate of 10 °C/min. The heat flow data were recorded and used to plot the heat flow curve.

Glass transition (T_g), defined as the inflection point of the transition temperature range, crystallisation onset (T_c) and peak temperature (T_x) were determined by differential scanning calorimetry (DSC; STA 449F1, Netzsch, 10 K min⁻¹ up to 1,300 °C, particle size 125–250 µm). In addition, T_g and dilatometric softening point (T_d) were measured by dilatometry (DIL 402 PC, Netzsch; 5 K min⁻¹ up to 1,000 °C). Thermal expansion coefficients (TEC; 100–300 °C) were obtained from dilatometry curves. Theoretical values for TEC were calculated using the Appen model from the glass compositions. This model takes the individual TEC contribution of each glass component into account^{34 ,49 (link)}. The glass processing window was calculated as the temperature range between T_g and the onset of crystallisation, as described earlier^{22 (link)}.
Heating microscopy (HSM/ODHT, Misura Expert Systems; HSM, 5 K min⁻¹) was used to measure changes in sample silhouette during heating. Characteristic temperatures such as beginning (i.e. onset) of sintering (T_so) and end (i.e. offset) of sintering temperature (T_se), start and the end temperature of crystallisation (T_xi, T_xf) as well as liquidus temperature (T_f) were recorded. Preparation of specimens for heating microscopy and subsequent analyses of curves were described previously^{12 (link)}.

Differential scanning calorimetry measurements were performed on a NETZSCH STA 449F1 equipment, capable of a maximum heating rate of 50 °C/s. A sample of the S700MC steel (approximately 1.5 × 2 × 3 mm and 75 mg) was placed inside an Al₂O₃ ladle and the measurements were carried out under a protective Argon atmosphere. The thermal cycles comprised four stages: 1 - holding at 100 °C; 2 – heating (at 50, 20, 10, and 5 °C/min); 3 - holding at 1000 °C; and 4 – cooling (at 50, 20, 10, and 5 °C/min). The cycles were carried out three times per heating/cooling rate. The holding times were 5 min.