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Currently, how to release the heat accumulated in the molten pool rapidly is the key factor in blade repair. We analyzed the problem of the current cooling method in blade additive manufacturing repair. Based on cooling effect, we proposed an advanced flexible multiflow path fixture cooling method for blade additive manufacturing repair. We created a coupled heat transfer model and deduced the heat transfer law for multiflow path conjugate flexible clamping. We obtained the optimal cooling scheme for flexible multiflow paths through numerical analysis. We built an experimental platform and tested the cooling effect of the fixture prototype by experiment. The results show that compared with the current cooling method, the new cooling method not only can lower the initial temperature of the fixture rapidly and realize the steady-state heat transfer between the fixture and the flow path quickly but can also significantly enhance the ability of fluid to participate in heat transfer in new flow paths, which significantly improves the cooling effect. The research results are of great significance for the improvement of aero blade additive manufacturing repair.

In this work, polypropylene (PP) film samples doped with an organic phosphorus nucleating agent under three cooling processes are examined for the effects of regulating the crystallization. The conductivity and DC breakdown strength of the film samples were tested at 25, 55 and 85 °C. The average breakdown strength with 0.01 wt% nucleating agent increased by approximately 25% compared to un-nucleating samples and the DC conductivity decreased slightly. For the three cooling methods in these tests, the slow process increased the crystallinity of the film samples and stabilized the electrical properties of the PP samples. It is concluded that improving the insulation performance through crystallization control is feasible, and this method shows great potential for the modification of PP films. [ABSTRACT FROM AUTHOR]