摘要 |
According to the invention there is now provided a cemented carbide button for rock drilling comprising a core (a) and a surface zone (b,c) surrounding the core whereby both the surface zone and the core contains WC (alpha-phase) and a binder phase based on at least one of cobalt, nickel or iron and that the core in addition contains eta-phase. The invention is characterized in that the eta phase core (a) extends to the very top working surface of the button and as result longer life and higher drilling rate are obtained particularly for rotary crushing drilling, cutting drilling and percussive drilling in soft rocks. <IMAGE> |