Deformation Research Of Ceramic Mud Extrusion Process

In the modern ceramic industry, extrusion molding technology is mainly used forproduction of ceramic products with constant cross section, has become the main forming andmodification methods, is widely used in various fields. But there are still many problems existin the process of practical production, the plastic ceramic mud easily appeared deformationdefects such as warping, distortion in the process of extrusion molding, cannot reach productsrequire geometry, then production process cannot proceed smoothly.Extrusion billet in cross section stress and extrusion speed inconsistencies may lead todeformation of ceramic products. Extrusion forming process of ceramic mud is in essence thelaminar flow of viscous fluid, the internal stress of extruding billet shows that the speeddifference between layer and layer. Use ANSYS CFX to numerical simulation of the ceramicrod extrusion molding process that change rules of the whole cross section’s velocitydistribution. The speed difference of Cross section’s three directions at outlet reached theminimum as the optimization goal, research the extrusion parameters on the extrusion billetinternal stress state and extrusion speed consistency, determine the reasonable combinationsof extrusion parameters, to make extrusion billet has reached the optimal stress state and aconsistent extrusion speed. Main research work include:(1) Make the single factor analysis on inlet pressure, moisture content, the length ofextension zone, extrusion cone Angle and reduction ratio, get the change rules of extrusionbillet’stress state and the consistent of extrusion speed. Determine the length of extensionzone, inlet pressure, moisture content, extrusion cone Angle as the main influencing factors,the reduction ratio is the secondary factor. Choose the factor level and design the orthogonalexperiment, through the orthogonal experiment results analysis, it is concluded that fourfactors of primary and secondary order and optimal combination. The CFD simulation resultsof the optimal combination show that the extrusion billet has reached a consistent speed andoptimal stress state.(2) According to different moisture content of ceramic mud, adopting the optimizeddesign module of ANSYS Workbench for extrusion molding tool (pressure head and die)geometric parameters design. Reasonable solving mathematical model is set up, which extrusion billet has reached the optimal stress state and a consistent extrusion speed, at thesame time to maximize production capacity. And according to the extrusion billet internalstress state and extrusion speed consistency changing with the reduction ratio, can use theresult of optimization design to achieve different diameter ceramic rod extrusion.(3) Under the condition of core rod in the center position, adopt the method of theoptimization design for ceramic pipe extrusion molding tool geometric parameters design,also can reached a consistent extrusion speed and the optimal stress state. Use the numericalsimulation method to extrusion process with the different thickness ceramic tube, study theeffect of wall thickness to the billet of ceramic tube. In actual production, the core rod oftenoccurs the mandrel eccentricity and tilt, analysis the effect of the core rod’s eccentricity andtilt Angle to extrusion tube, and positioning precision of the eccentric is given.