PT Journal
AU Bassoli, E
   Denti, L
TI Investigation on the Effectiveness of Through-hole Replicas of Deep Small Holes
SO Manufacturing Technology Journal
PY 2018
BP 357
EP 362
VL 18
IS 3
DI 10.21062/ujep/105.2018/a/1213-2489/MT/18/3/357
DE Electro discharge drilling; quality control; silicone replica; high aspect ratio hole; roughness measurement
AB When a micro-hole of high aspect-ratio is required, in addition to machining problems, special attention should be paid to controlling the quality of the manufactured products. Dimensional and surface metrology in the field of micromachining can be as critical as machining itself, therefore several new measurement methods have been developed. However, many of these methods suffer from application limits when used in the case of a deep hole. Replication can be a useful approach, which has well-proven validity in the time-consuming case of the sectioned hole. The method of through replicas, to be pulled out of the unsectioned hole, still needs verification.In the present paper, the surface roughness of deep small electrodischarge drilled holes is measured, and the effectiveness of the use of both open- and through-replicas is evaluated, versus direct measurements on the micro-drilled surfaces. Through-hole replicas, by means of injection and extraction of a silicone, are proven reliable for reproducing the surface morphology of holes down to 0.8 mm diameter with an aspect ratio of 12.5. The findings show that the operative range of the considered techniques may be extended with respect to the previous cases mentioned in literature
ER