An Advanced Flexible Multiflow Path Fixture Cooling Method for Additive Manufacturing Repair of Aero Blades

Abstract

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. INDEX TERMS Cooling method, blade repair, flexible fixture, numerical analysis, heat transfer.

Modeling of additive height and numerical analysis of cooling parameters for aero blade remanufacturing

“…Due to the temperature of the contact surfaces between the copper bonds and the blade being less than 427 • C, the thermal radiation resistance can be neglected (Bahrami et al, 2004a). The thermal contact resistance model can be seen to in other works (Zheng et al, 2014;Shi et al, 2018;Tariq et al, 2016;Yovanovich et al, 2006;Grujicic et al, 2005;Bahrami et al, 2004b) and our previous research (Dai et al, 2020b).…”

“…Because the test piece is very thin, there is a certain degree of horizontal error in the manual polishing of the upper surface before welding, so the morphology after surfacing has a certain degree of tilt. According to the experimental parameters obtained from previous studies (Gong et al, 2019;Dai et al, 2020a), the cross section morphology of the additive zone of two kinds of wire-feeding speeds (6 in min −1 (2.54 mm s −1 ) and 8 in min −1 (3.39 mm s −1 )) was measured by software. The results show that, although the cross sectional morphology is inclined to a certain extent, the roundness of the additive morphology of the two wire-feeding speeds is good, which is consistent with the theoretical model.…”

“…In this paper, the coupled heat transfer model is mainly composed of solid heat transfer and fluid heat transfer. The model equations can be referred to in our previous research (Gong et al, 2021). In addition, for heat conduction in the microstructure, the effect of thermal resistance on the overall heat transfer should be considered (Wang et al, 2021).…”