boring-methods-for-cooling-airFused splashes around the opening of a laser bore:Metallographic cut through bore surfaces that were melted open in process-specific ways: 0.1 mm0.1 mmLaser boreEDM boreEmbrittled, hardened, and crackedrecast layer with high tensile residualstresses Melt burr reduces throughflow Bore openingSpattered flat particles; when they separate, there isan increased danger that the cross-section will be shifted.Spherical particles; when they separate, there is a dangerof smaller cross-sections (e.g. dust removal bores) shifting Potential finishing-related problems of different boringmethods for cooling air bores in turbine blades:PartGlass pipeElectrolyteHydrogengas bubbleblocks electrolyteflow; minormaterialremovalElectrolyteflow is free;heavymaterialremovalPhase 1Phase 2Formation of circumferential grooves and corrosive attack duringelectro-chemical precision drilling:0.2 mmAufgetrennteBohrung mitbesonders starkausgeprรคgtenRillenGrain boundary attackPitting corrosionca 0.5 mm