Machining Process Optimization Of Nickel Alloy Rhombic Turbine Blade

Nickel alloy blade is used more and more often in the turbine.Process of this kind of blade usually adopts lower cutting parameters due to the hard machining properties,which lead to long processing time,high processing cost and heavy tool loss.This paper is devoted to optimize the machining process of nickel alloy blade so as to reduce the processing costs and enhance the manufacturing efficient with the assurance of the machining quality.The primary research work and achievements include:1.A new process plan for nickel alloy blade machining from raw material to final product is developed.Steel blank is selected as the raw part by comparing the steel blank cost with the forging cost.The rhombic blank sets are analyzed including the material utilization ratio and the processing cost.Based on the blade process of common material,wire cutting and four axis NC machining are adopted to remove most allowance of the nickel alloy blade before the final process with five axis NC machine,to reduce the finish cutting time and the whole processing cost.2.An innovate fixture is designed to assure the valid fixing of the blade with position error cones on the blade ends.The fixture of the blade was improved by using the pinion and rack mechanism,which eliminates the blade's axis positioning accuracy influence on jaw position.The design of the fixture has been used to apply for the national invention patent in China.3.The rough milling cutter design and the finish milling parameter optimization is conducted.A new ball end milling cutter was designed for rough machining of the blade airfoil.Solid carbide and chip removing groove was used to increase the tool life.The orthogonal cutting test of nickel alloy blade airfoil finishing machining was designed to optimize the cutting parameters of the ball end milling cutter on the five axis NC machine,which ensures the machining with qualified finish and increased tool life.