| dc.description.abstract | Homogenized Cu-4Ti (wt%) and Cu-4Ti-1.4B (wt%) powders were cold pressed and then sintered by pulsed, millisecond Nd:YAG laser system. Phases present in laser sintered samples were characterized by X-ray diffraction (XRD), while quantitative chemical analysis of the sintered samples was conducted using inductively coupled plasma-atomic emission spectrometry (ICP-AES). The microstructure of powders and laser sintered foils was examined with scanning electron microscope with an energy dispersive X-ray spectroscope (EDS). Optical microscopy was used also for microstructural characterization of the foils. The tensile test was carried out using a universal testing machine with a crosshead speed of 0.5 mm/min at room temperature. Foils with dimensions 20 × 6 × 0.4 mm were used for tensile testing. In the obtained Cu-Ti foils, after aging at 550 °C for 4 h, rapidly solidified structure and metastable Cu4Ti precipitates affected high degree of copper matrix strengthening (peak aged). In Cu-Ti-TiB2foils, after aging at 550 °C for 3 h, rapidly solidified structure, as well as the presence of TiB2particles and metastable Cu4Ti precipitates, also affected high degree of copper matrix strengthening which, thanks to the ceramic particles, is retained at longer times (6 h). Fractured surfaces were observed with an optical microscope. It was determined that the best structural and mechanical properties of laser-sintered foils were reached using the following parameters: laser frequency 4 Hz, laser pulse duration 9 ms, pulse energy ∼20 J, number of scans 2. | en |
