Method and device for the finish machining of gas-turbine engine blades cast in a brittle material

A method for the finish machining of blade root structure of gas-turbine engine blades cast in a brittle, light material, the structure including an airfoil and a platform, which upon removal from a casting mold is connected to a casting structure of feeders and runners, comprising:

• clamping the structure to a workpiece carrier using the feeders and runner portions remaining on the platform of the blade as an auxiliary clamping structure with the blade airfoil being first positioned at reference points defined for subsequent machining,
• afterwards fixing longitudinal sides of the platform with a runner clamping surface having conical recesses and threaded holes (14) originating at these conical recesses being subsequently produced in this defined position on the runner portions, with the workpiece so prepared being centrally positioned and clamped on the workpiece carrier in a flexible taper fit and then machined at the blade root structure, and
• severing the auxiliary clamping structure from the machined blade.