Ultrasonic assisted creep feed grinding and dressing of advanced aerospace alloys

[摘要] The research involves the investigation of hybrid ultrasonic assisted creep feed grinding (UACFG) of advanced aeroengine alloys, in particular Inconel 718, CMSX-4 and gamma titanium aluminide (γ-TiAl). For tests with ultrasonic vibration, workpieces were actuated at a constant frequency (~20kHz) via a specially designed block sonotrode attached to a 1kW piezoelectric transducer-generator system. The trials on nickel based superalloys were carried out using open structured alumina wheels whereas γ-TiAl specimens were machined with conventional silicon carbide and single layer diamond superabrasive wheels. Statistically designed experiments involving variation in wheel speed, table speed, depth of cut, grinding condition and vibration amplitude were employed in mainstream testing. Reductions in grinding force components were typically observed albeit at the cost of higher wheel wear and surface roughness of the ground slots when ultrasonic assisted grinding of nickel alloys. Conversely, UACFG of γ-TiAl exhibited lower grinding wheel wear and workpiece surface roughness. Surfaces ground with the assistance of vibration generally revealed greater side flow/ploughing and overlapping grit marks in comparison to standard creep feed ground specimens. Three dimensional topographic measurement of grinding wheel surface replicas indicated that ultrasonic vibration led to an increase in the number of active cutting points on the wheel.

[发布机构] University:University of Birmingham;Department:School of Engineering, Department of Mechanical Engineering

[关键词] T Technology;TJ Mechanical engineering and machinery