Product Code: PIC2008_1104

Topographic Analysis of Holes Drilled by Pulsed Nd:Yag Laser on Dd6 Single-Crystal Superalloy
Authors:
Chen Changjun, Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Laser Processing Research Center; Wuhan Peoples Republic of China
Zhang Min, Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Laser Processing Research Center; Wuhan Peoples Republic of China
Zhang Shichang, Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Laser Processing Research Center; Wuhan Peoples Republic of China
Chang Qingming, Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Laser Processing Research Center; Wuhan Peoples Republic of China
Yan Wenqing, Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Laser Processing Research Center; Wuhan Peoples Republic of China
Zhang Xiaobing, Key Laboratory for High Energy Density Beam Processing Technology; Beijing Peoples Republic of China
Presented at PICALO 2008

Modern aerospace gas turbines require large numbers of small diameter holes(1mm) to provide cooling in the turbine blades, nozzle guide vanes,combustion chambers and afterburner. A typical modem engine will have about 1 00,000 such holes. drilling these cooling cooling holes in such components by ND: YAG laser is now well established. In the engine, turbine blades must safely sustain temperatures as high as 1,500°C. To keep blades from melting, they are provided with cooling air holes, through which they are cooled. The air functions as a protection layer between the blade and the hot gas. In laser-drilling, a laser beam is focused onto the blade surface and the high energy density causes the material to fuse.ingle crystal nickel base superalloy turbine blades are being utilized in rocket engine turbopumps and turbine engines because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over polycrystalline alloys.In this paper, Laser drilling is used to manufacture cooling holes in DD6 single crystal supperaloy. Holes having diameters about 580μms were percussion drilled with a ND: YAG laser.Topographies of holes in DD6 single-crystal superalloy by pulsed ND: YAG laser were analyzed.Recast layers, microcracks and spatters were found on the hole-walls.And the morpgology of the recast layers,microcracks and spatters were clearly revealed by scanning electron microscope(SEM) in the present study.