Rapid Heating Method For Hot Stamping Process And Isothermal Micro-nano Hot Stamping Process

With the rise of the Internet of Things,Internet+,and intelligence,the structural components in various fields are developing toward small and portable,and micro-component micro-systems have become the protagonists of various frontier fields.The traditional "macro" mechanical manufacturing technology is in the current field of micro-nano processing and manufacturing,and it has been difficult to meet the high-precision manufacturing requirements of micro-machines and micro-systems.Under this background,the high-polymer micro-nano-embossing technology has been developed at a high speed by virtue of its low cost,easy processing and high self-replication accuracy,and has become a research hotspot in the micro-nano manufacturing industry.Professor Wu Darming from Beijing University of Chemical Technology has taken a different approach and innovatively proposed an "isothermal hot stamping process" from the molding process,breaking the periodic variable temperature of "high temperature imprinting-low temperature demoulding" of the traditional hot stamping process.Under the shackles of thought,the embossing cycle of 10-15 min was shortened to about 20s without increasing the cost of any equipment,which laid the cornerstone for the industrialization of the process.Based on the isothermal hot stamping light guide plate process,this paper proposes a suitable electromagnetic induction rapid heating method.The combination of the two makes the hot stamping process further approach the ideal state of its thermal load,completely eradicating the preheating stage of the mold,and shortening the imprinting again on the basis of the isothermal hot stamping process.The cycle reduces the proportion of embossing defects,which is undoubtedly awesome for the isothermal embossing process.For this purpose,this paper takes the spiral induction coil disc mold as the research object,and surrounds the intermal relationship between the heating effect of electromagnetic induction and the working current,and how to establish the current parameter of induction heating suitable for hot stamping process.The core issues such as value are studied in depth from the construction of mathematical models,based on the numerical simulation of Comsol software and the verification of the experimental platform.The combination of the three aspects forms a complete closed loop of the theory-simulation-experimental mutual proof,which has certain guiding significance for the application of electromagnetic induction rapid heating in the hot press forming process.The research results are as follows:1.Based on the electromagnetic induction theory based on Maxwell's equations,the important parameters for quantitatively characterizing the electromagnetic induction heating effect are established,and the mathematical model for the penetration depth and heating power of the spiral induction coil is established.The electromagnetic-thermal coupling numerical simulation was carried out by using COMSOL finite element analysis software.The relationship between the operating current and frequency of the electromagnetic induction heating unit and the key factors such as mold heating rate,heating depth and temperature distribution uniformity was quantitatively studied.Mathematical model,and determine the suitable current range of the electromagnetic induction heating device in the hot stamping process,which has certain guiding significance for the application of electromagnetic induction heating in the hot press forming process.2.In order to further verify the accuracy of the mathematical model and COMSOL software numerical simulation analysis results,the electromagnetic induction experimental platform was designed and built,and related series experiments were carried out.With the aid of Fluke TiS65 infrared thermal imager,the mathematical model and numerical simulation were carried out.The analysis results are verified,and the applicability of the mathematical model is proved,forming a complete closed loop combining theoretical simulation experiments.3.The rapid heating effect based on electromagnetic induction further optimizes the isothermal hot stamping process,and innovatively superimposes the three stages of heating,pressure holding and cooling into one stage,which not only greatly shortens the molding cycle,but also improves the product.Forming quality.Then,the common defects in the process of isothermal hot stamping of the light guide plate are classified and summarized,and the causes of the most common bubble defects and incompletely filled defects are analyzed,and an effective and easy to implement optimization is proposed.