A shrinkage cavity model based on pressure distribution for Ti-6Al-4V vertical centrifugal castings

摘要

Vertical centrifugal castings from Ti-6A1-4V alloy are investigated, with detailed analysis of evolution of isolated liquid volumes and shrinkage location in each isolated liquid volume, in order to predict the shrinkage cavities. Based on the minimum potential energy principle, the shrinkage distribution rule and boundary criterion used in the search algorithm for isolated liquid areas were formulated. The applied boundary criterion estimates the critical pressure, at which an isolated liquid volume can be fed by another one. In each isolated liquid volume, the shrinkage cavities would be distributed at the zero isostatic surface. Pressure values are critical for the proposed shrinkage cavities prediction model, the flowchart and solutions for which are discussed in detail. The proposed model feasibility was verified by a series of the U-type vertical centrifugal casting experiments and simulations on Ti-6A1-4V alloy.