High-efficiency milling of steam turbine blade

Conventional methods often use ball end mills with a small diameter to finish machining of a steam turbine blade to satisfy accuracy requirements by using a small pick feed value. Thus, the cutting length increases, resulting in increased wear and a lower milling efficiency. Therefore, a new method using a tilt-taper end mill is proposed. This paper presents the validity of the proposed method used for milling planes by comparing the ball and square end mills through tool wear experiments. Factors including removal degree, surface roughness, tool wear, and machined surfaces are investigated with respect to the plane model. The experimental results show that tilt end mill can retard the tool wear remarkably to obtain a steady surface profile, and the maximum surface roughness value, using the tilt-taper end mill, is less than 6 µm until process completion. © 2016 Fuji Technology Press Ltd. All Rights Reserved.