Experimental Study On Nickel-based Composite By Ultrasonic Assisted Magnetic Abrasion

With the rapid development of science and technology,the application of nickel base alloys is more and more extensive.Because of its high strength,strong corrosion resistance,high creep strength and fatigue resistance at 650~1000 ℃,and good thermal stability and thermal fatigue resistance,it is widely used in aviation,aerospace,petroleum,environmental protection,nuclear industry,energy and other fields.Used for manufacturing aero-engine space elbow,special-shaped pipe,large-scale petroleum equipment and chemical equipment in the pipeline.Because the tubular parts are processed by hot extrusion and oblique piercing,there are some residual tensile stresses in the tubular materials and a large number of pits,bulges and microcracks on the inner surface,which seriously affect the comprehensive performance of the tubular parts.Therefore,it is particularly important to improve the stress state and micro-crack defects of the profiled tube,reduce the surface roughness and improve the surface quality.As a special machining method,magnetic particle abrasive finishing(MPA)is widely used in special material plane,complex curved surface,space elbow,inner and outer surface finishing because of its advantages of self-adaptability,self-sharpening,small temperature rise and no tool compensation.But its cutting performance is poor,processing efficiency is low,and can not meet the needs of today’s industry.Therefore,an ultrasonic vibration assisted magnetic particle abrasive finishing method is proposed in this paper.The ultrasonic high frequency vibration is transmitted to the magnetic abrasive particles,which makes the particles roll and impact the surface of the workpiece at high frequency,increases the force of the magnetic abrasive particles on the workpiece,and then rotates the spindle to make the magnetic abrasive particles.To scratch the workpiece material,this method is to effectively combine the two kinds of special processing,highlighting their respective processing advantages of a processing method.Based on the effective combination of ultrasonic special machining and magnetic abrasive finishing,the principle of ultrasonic special machining and its experimental research are discussed in this paper.Response surface methodology was used to conduct interactive analysis of two factors.The influence of spindle speed,magnetic abrasive particle size,ultrasonic amplitude and ultrasonic frequency on the surface roughness of workpiece and the residual stress state of workpiece surface after machining are analyzed.The results show that the ultrasonic-assisted magnetic abrasive finishing method is more efficient than conventional magnetic abrasive finishing,and the surface quality and morphology are improved obviously.The original residual tensile stress of the workpiece is transformed into compressive stress,and a better surface stress state is obtained,which verifies the feasibility and effectiveness of the test.