GB868989A - Improved method for the production of blades for gas turbines or compressors - Google Patents

Abstract

868,989. Making turbine and like blades. GARRINGTONS Ltd. May 21, 1959 [May 27, 1958], No. 16791/58. Class 83 (2). A turbine or like blade with at least one internal passage for heating or cooling fluid is made by forming at least part of a blank having an internal passage or passages into an elongated cross-section, such as oval, filling each passage with a removable material, forging the blank in a direction substantially parallel to the major axis of the elongated section and finally removing the filler. A hollow cylindrical billet with a cylindrical through bore, Fig. 1 (not shown), is first partly extruded through a die of oval shape and over a tapered mandrel which forms it to the shape of Fig. 2 with a tapered bore 14. The bore is then filled with mild or alloy steel rod or wire and the portion 16, Fig. 3, is forged between dies acting-parallel to the major axis of the extruded section. This causes the bore to be elongated into a slot 15, Fig. 3A. The end portion 20 serves as a locating tap for future operations. Excess metal is then trimmed off, the blank is machined and forged in two stages, Figs. 5, 6 to form the aerofoil profile and twist the blade. The root and aerofoil portions are finally finished by grinding or machining and the filler is dissolved out by acid. Other embodiments are described for forming a shrouded blade, Fig. 8 (not shown), or a blade with a plurality of passages, Fig. 10 (not shown).