Titanium alloy is difficult to dry-drill due to its properties, such as low thermal conductivity and adhesion. Previous studies indicated that adding low-frequency vibration to the drill axis can reduce drilling temperature, and extend tool life. In this study, the drilling temperature of the cutting edge was measured by the tool–work thermocouple method. The results showed that the temperature of low-frequency vibration drilling was almost equal to that in the conventional method even though the cutting thickness was increased, and with low-frequency vibration drilling the temperature decreased during the non-drilling time. On the other hand, in the case of conventional drilling, tool life decreased with increasing cutting thickness. Therefore, comparing the low-frequency vibration and conventional method, the temperature was equivalent, but the actual drilling distance became shorter by non-drilling time and tool wear was reduced.

View full abstract

In this study, the effects of injection angle on the processing depth of silicon wafer and aluminum were investigated using the wet blast technique. The effects of injection angle and injection distance on the textured surface were investigated. The test slurry was pure water containing angular alumina particles 1.2μm in diameter. The injection angle was set to 30° or 90°. At an injection angle of 30°, when the number of processing cycles was ≥ 4, a surface with protruded silicon was produced. At an injection angle of 90°, with ≥ 8 processing cycles, the surface with dimpled silicon was produced. At 20 processing cycles, when injection distance was from 2 to 6 mm, textured surfaces were produced.

View full abstract