Numerical Simulation Of Large Dimension And Thin-wall Ceramic Cylinder Liner During Cold Isostatic Pressing

The advanced structural ceramics show a variety of good properties, such as high strength, heat-resistance, wear-resistance, erodent-resistance, which display excellent performance in severe work-conditions, and chanllenge the metallic products used in the fields of metallurgy, mechanical engineering, national defense and aviation. The entoughness ceramics cylinder liner, in use of the good physical properties of ZrO2, which of high strength, wear-resistance, erodent-resistance, was developed at Tianjin University.The entoughness zirconia ceramics cylinder liner can be made by CIP with many factors and complexes forming laws. The drawback of CIP is low efficiency, and forming depends on the experience of the designers and experiments. The method of finite element simulation allows mastering the forming laws of powders, and the effects of various factors, which is attractive to improve forming qualities, and development of technical.The objective of this work is to displays the deformation rule, flow rule of powder, density distribution, stress and strain distribution laws in CIP of ceramics cylinder liner. The effects of the forming parameters on the forming were also studied. Results showed that the powders closed to the die walls densified first. The densification regions extended to the outer, with the difference in the geometric and green density of below 1%.As for the unloading, a lower rate of unloading ehanced densification, and a two stages of unloading further improved the uniformity of density distribution, and reduced the area of density gradient at the left-up corner. These results help to update the unloading safety of green body.A higher pressure enhanced densification, and the pressure above 200MPa suppressed spring-back of the compacts. Unloading became more safe.The pressure slightly above 200MPa improved the rate of finished product and demolding.The use of rigid plug showed little effect on density, but gave smooth green bodies at the top. The green bodies of the"elephant foot"shapes have less density gradient as the result of the good forming performance.