Production of Hard Materials with Ubiquitously Fe-B System by Spark Sintering and their Characteristics

Abstract

The spark sintering technique was utilized to fabricate ubiquitously hard-materials compacts which were 0, 10 and 50vol%Fe added (hereafter called, 100, 90 and 50%FeB, respectively) in as-received powders with mean composition of Fe-19.1wt%B. Rockwell hardness number on C scale was changed 63 to 70 depending on Fe contents, and the value of 100%FeB compact was the same as that of WC-7.8Co. The 100 and 90%FeB compacts showed the fracture strain of 0.32 and 0.41 %, or fracture stress of 212 and 133 MPa, respectively, in three points bending tests at room temperature. The 100%FeB compacts had the same level in fracture stress and increment of 0.1 % in fracture strain at 773 K, compared with those obtained from the bending tests at room temperature. Dynamic friction coefficient of 90 and 100%FeB compacts was lower than that of WC-7.8%Co in pin (SK2) on disk configuration. Same values were shown in both wear loss on specimens (100%FeB or WC-7.8%Co), and SK2, which meant the similar level in these compacts for the cutting performance as the tool materials. The value of flank wear width (VB) was 0.26 mm at cutting distance of 30 m for the work material of Ti-6Al-4V using the cutting tool of 100%FeB, which meant the satisfaction for its standard value of 0.3 mm as the life of tools.