Research On Hole Enlargement Defect During Hot Power Backward Spinning For7075Casting Aluminum Alloy Tube

Hole-enlargement is an inevitable phenomenon in hot power backward spinningforming of casting high strength aluminum alloy tube in the process. It affects theforming quality of the tube parts seriously. However, the power spinning of the tube isone of complicated forming processes characterized by3D continuous-local,heterogeneous deformation and unsteady state, under the action of multi-fields,multi-factors and their coupled effects. Research of thin-walled tube parts preventionand control of hole-enlargement phenomenon is extremely challenging. For thispurpose, this paper takes7075casting aluminum alloy thin-walled tube parts of hotpower backward spinning forming defect hole-enlargement as the research object, andstudied the research development and evolution of hole-enlargement by using finiteelement numerical simulation mostly combined with the experiment and theoreticalanalysis. The influence laws of process parameters of hole-enlargement were obtained.A brief introduction of this paper and its main results are follows:(1) A3D-EF model of hot power backward spinning forming of7075castingaluminum alloy tube was established in accordance with the actual based on Abaqusfinite element platform and its reliability is validated by experiment.(2) The hole-enlargement deformation behavior of hot power backward spinningof7075casting aluminum alloy tube are obtained, and presents the quantitativecharacterization of hole-enlargement. Reveals the process of the hole-enlargementwas along the distribution characteristic of the axial and circumferential tube parts andhole-enlargement is the changes characteristics in the spinning process.(3) The influence laws of the preheating temperature of the blank, thinning rate,wheel feed, the friction between the wheel and blank, spindle speed, and on the tubeend attachments to the hole-enlargement (bell mouth) is achieved. The result showsthat: With the increase of the preheating temperature of the blank, thinning rate, wheelfeed, the tube hole-enlargement degrees are more and more, while under the influenceof the spindle speed, degree of hole-enlargement presents the ups and downs, but theinfluence of the friction between the wheel and the blank is not obvious.(4) Based on the influential rules of process parameters on the deformation to thehole-enlargement forming of casting aluminum alloy tube, the rank of reasonable process parameters can be worked out when the hot power backward spinning of athin-walled of7075casting aluminum alloy tube is forming. The reliability of theresults is verified by the experiments. It provides the basis for the choice andoptimization of the power spinning of tube process parameters.