Özet:

In this study, tungsten boride (WB and W2B) based composites with various amounts of tungsten disilicide (WSi2) addition were fabricated by using a combined method of mechanical milling (MM), cold isostatic pressing (CIP) and pressureless sintering (PS). MM was conducted for 4 h in ethanol (wet milling) and Argon atmosphere (dry milling) using a high-energy ball mill. WSi2 was used with different amounts (0, 5, 10 and 20 wt.%) in order to investigate its effect on the resultant products. MM’d powders were compacted using CIP under a pressure of 450 MPa, and were consecutively sintered at 1600 °C for 2 h and 1770 °C for 2 h under Ar atmosphere. Compositional, physical and microstructural characterizations of the samples were performed using stereo and optical microscopes, X-ray diffractometer, TOPAS software, scanning electron microscope coupled with an energy-dispersive spectrometer, particle size analyzer and gas pycnometer. Sintered products were also characterized in terms of Archimedes density and Vickers microhardness. Moreover, the oxidation studies of the samples were performed at 500 and 1000 °C via thermogravimetric analyzer. The results showed that the highest density, microhardness and oxidation stability values amongst the fabricated composites were obtained for the dry milled and sintered WB-20 wt.% WSi2 sample. 

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