An analysis of canned extrusion using analytical methods and the experimental extrusion of cast IN100
This work deals with the plastic deformation and temperature analysis of the coextrusion process known as canned extrusion. Analytical techniques such as the upperbound method, slab method, lumped parameter method, and the finite element program, ALPID, were used to analyze the coextrusion of IN100 in a 304 stainless steel can. The effects of can thickness, can flow stress, core flow stress, and heat transfer parameters on load, material flow, states of stress, strain, and strain rate were investigated and correlated with experimental extrusions. The experimental extrusions demonstrated the effect of average effective strain on the microstructure of cast IN100 and the effect of canning on surface defects. The occurence of the fir tree surface defect correlates very well with the transition from compressive to tensile axial stress. This defect can be avoided in brittle materials, such as cast IN100, by placing the brittle material in a can of ductile material with an approximately equal flow stress. The addition of an insulating material at the can/core interface would be more effective than glass lubricants at the die/billet interface in reducing heat loss. An average effective strain of 1.8 transformed the as-cast IN100 grain structure to a fine recrystallized grain structure while a strain of 1.2 did not. Finally, this investigation has combined analytical modeling with experimentation to provide a quantitative understanding of the state of stress, strain, strain rate, and temperature during the coextrusion of canned billets.
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:canned extrusion analytical methods experimental cast in100
Date of Publication:01/01/1990