Predication and control of chaotic characteristics by the maximum Lyapunov exponents in PIM filling process

Model geometry and technological parameters have important effects on formation of forming defects in the mold filling process of powder injection molding (PIM). The maximum Lyapunov exponent was used for the research on chaotic characteristic in PIM Filling Process. Based on mathematical model of the PIM filling process, computer simulation method is presented for this process and the time series of speed azimuth are extracted for calculation of the maximum Lyapunov exponents. The maximum Lyapunov exponent is used as a criterion to determine whether PIM filling process produces chaotic characteristic or not in the cavity of complex models. The result of computer simulation shows that the locations of defects are mainly in the apex angle and the position away from the entrance. Furthermore, process parameter such as injection temperature has been investigated respectively by the method of grid transient analysis, in order to analyze the impact of technological conditions for chaotic characteristics and control products defects in PIM filling process.