2.2. Characterization
The phase compositions of the samples were identified by X-ray diffraction
(XRD, Model: D8 FOCUS) with Cu Ka radiation (k = 0.154178 nm) through a continuous
scanning mode at a speed of 2/min. The densities of the sintered hard alloys
were determined by the Archimedes’ water immersion method. The reported
relative density values were the average of three test results. The microstructures
of hard alloys were examined using an environmental scanning electron
microscope (ESEM, HITACHI, S-4800) with a link EDAX system for local chemical
composition analysis. The hardnesses were measured by a Vickers micro-hardness
tester (FM-700, Japan) with a load of 30 kgf and dwell time of 15 s. The reported
hardness values were the average of four measurements. The transverse rupture
strength was measured at room temperature by a three-point bending method
on an Instron model 1125 test machine with a loading rate of 2 mm/min and a
length span of 30 mm. The samples dimensions (5 mm 5mm 38 mm) and the
testing procedure was in accordance with the China’s Standard YB/T 5349-2006.
The reported transverse rupture strength values were the average of three
transverse rupture test results.