Experiment And Numerical Simulation Of Online-quenching Process For Complex Section6xxx Aluminum Profiles

As an important link of complex section aluminum profiles production, online quenching can greatly affect the property of the product, especially during the critical temperature range; For the uneven cooling rate in different parts of complex profiles, it is prone to be bended, distorted or warped, only to reduce the production. The cooling curves of6061,6063aluminum alloy under strong wind and different water flow were accqired via end quenching experiment; The corresponding surface heat transfer coefficients were also calculated with numerical methods; Combined with ABAQUS software, on-line quenching process of different alloys, different flows, profiles with different sections were analysed through numerical simulations.The results suggest:1) Regardless of wind or water quenching, cooling of specimens correspond with one-dimensional heat transfer model, the closer the area is to the quenching end surface, the greater the cooling rate will be; Cooling of6061and6063aluminum alloy are similar, and in the same quenching conditions, the cooling rate of6063aluminum alloy is relatively larger.2) The relationship between surface heat transfer coefficient and the corresponding temperature is non-linear. At the beginning of the quenching process, the heat transfer coefficient tends to increase within the reducing of the surface temperature; The value of surface heat transfer coefficient in water quenching is much larger than that in strong wind quenching.3) Cooling disciplines of Profiles with two alloys in the same quenching conditions are basically the same; during the cooling process, the overall temperature gradients increases firstly, then decreases, and the maximum value exceeds100℃. The average cooling rates of6063aluminum profiles are significantly greater than that of6061aluminum, while6061aluminum alloy profiles get larger thermal stress during quenching process. 4) The temperature drops the most stable with strong winds quenching, and the temperature gradient is minimal, but the cooling rate is too low; Cooling rate is the largest when water flow is0.64m3/h, but temperature drops the most unstable; With water flow of0.2m3/h and0.32m3/h, the cooling rate is relatively large and the temperatures drop stably. Peak stress value of strong winds quenching is the minimal, and stress changes stably during quenching process; Compared with water flow of0.2m3/h and0.64m3/h, peak stress value is the lowest with the flow of0.32m3/h.5) The increase of water flow can effectively improve the cooling rate of profiles; By comparing simulated quenching results of profile with different water flows, the optimal water flow is defined as0.32m3/h.6) Cooling laws of the profile, which are accquired from quenching experiments and simulation, are in good agreement with the actual production, which indicates the correctness of the calculated heat transfer coefficients and the validity of the numerical simulations, which have certain significances for the design of production process and the elimination of quenching residual stress.