Research On Abrasive Belt Grinding Of Blisk Blade Inner And Outer Profile

The blisk is a new type of components for high performance aero-engines mainlyused to improve the thrust-weightratio, and has been widely used in the new generationaero-engines. Blades which have complicated structure and high precision are keycomponents of aero-engines, turbines and other equipments. The quality of processingfor blades can directly affect the performance of entire equipments. The material ofblades which are used in high temperature, high pressure and high-speed situations havehigh mechanical property, high chemical stability, high hardness and low coefficient ofthermal expansion that makes its processing characteristics poor. Blisk has thecharacteristic of complex blade surface, narrow channel between blades, easy todeformation and difficult to machining. The blisk blade surface is designed by thetheory of aerodynamic. Processing quality of blisk has a significant impact on theperformance and service life of the aircraft engine, so it is critical for blade surface tohave high accuracy and surface roughness.The blisk is firstly machined by NC milling or electrochemical machining and atlast by grinding and polishing process. Blisk polishing is used for the residual millingmarks removal and quality improvement of blade surface. The manual polishing methodwhich is widely used at home has the disadvantage of low processing efficiency, unevensurface and poor surface consistency. In view of this kind of current situation, this thesishas put forward the grinding and polishing method for blisk blade inner and outer arcprofile, aimed to implementation the finish machining of blade surface.The main contents and research results are as follows:①Analyzed the material properties and grind ability of difficult-to-machinematerials used for blisk.②According to the structural features and processing requirements of blisk blade,analyses the difficulties for blisk blade surface grinding. Then present the free surface ofsix axis CNC abrasive belt grinding principle and through the single grain verticalcontact pressure model analysis, analyze the mechanism of action of grinding to verticalcontact pressure. Afterwards, analyzed the NC belt grinding process of blade profile,determined the processing tool path, simultaneously analyzed the contact wheel, beltand the selection of grinding parameters.③Seven basic freedoms are identified through the analysis of the structure characteristics of the blisk and put forward the configuration scheme for abrasive beltgrinding of blisk blade profile. Propose the contact pressure control scheme for abrasivebelt grinding and establish the pressure control model, then obtain the basiccharacteristics of system by simulation analysis, ultimately, the grinding head structureis designed.④Carry out CNC abrasive belt grinding process test of blisk blade, in view of theimportant evaluation index of surface quality, carry on research about surfacemorphology, surface roughness. Establish the surface roughness model about processparameter sensitivity, analyzing the influence of the belt speed, grinding pressure,abrasive belt particle size, feed speed on each index, then obtain the optimized processparameter interval.