METHOD FOR HARD-ALLOY DRILL BIT TOOTH QUALITY CONTROL Russian patent published in 2008 - IPC G01N27/00 

FIELD: drilling equipment, particularly to control quality of hard-alloy teeth used in rock cutter bits.

SUBSTANCE: method involves preparing microsections; installing microsections on microscope stage; performing visual structure investigation by surface pattern comparison with models; drawing a conclusion about defect types and possibility to use sintered wolfram-cobalt hard alloys. Electric spark erosion etching, which provides flat local zones fusing and evaporation, is used for microsection preparation. The electric erosion etching exposes part of three-dimensional surfaces and boundaries of separate grains with pattern of defect and porosity distribution at exposed cobalt grain boundaries. Three-dimensional cobalt phase defect distribution pattern supplements widely-used metallographic hard alloy quality control methods.

EFFECT: improved visualization of hard-alloy cobalt phase structure.

6 dwg