New Al - Zinc - Mg - Cu High-strength Aluminum Alloy For Free Forging Numerical Simulation And Experimental Research

The thick plates of Al-Zn-Mg-Cu aluminum alloys with high strength havea very wide range of applications in the field of military and civilian facilities.Multi-directional forging technology has become the main technology ofpreparation of super-high strength aluminum alloy thick plates because of itssimple process, low cost, and better performances. Therefore, it has theimportant significances for production of aluminum alloy thick plates with highperformance by studying of multi-directional forging technology of aluminumalloy.Multi-directional forging process of a new Al-Zn-Mg-Cu super-highstrength aluminum alloy under different times of upsetting and stretching anddifferent ways of broadening was studied systematically in this paper. Specificresearch contents and results are as follows:1. Upsetting and stretching in the process of multi-directional forging weresimulated by Deform software, and the process parameters such as the ratio ofanvil width to billet height, and reduction were analyzed. The results show thatwhen the ratio of anvil width to billet height is0.6and reduction is15%-25%,the effect of stretching is better.2. Multi-directional forging processes which were conducted by thescheme Ⅰ of three-times upsetting and twice-stretching with broadening bydrawing and the scheme Ⅱ of four-times upsetting and three-times stretchingwith broadening by drawing were simulated by Deform-3D. The results ofsimulation show that the equivalent strains in simulated forgings by the schemeI and Ⅱ are7.5and11.1respectively. The forging ratio of the scheme Ⅰ isgreater about4.04than that of the scheme Ⅱ. The value of equivalent strains bythe scheme Ⅰ is greater3.6than that by the scheme Ⅱ.3. Multi-directional forging processes which were conducted by thescheme Ⅲ of twice-upsetting and twice-stretching with broadening by upsettingand the scheme Ⅳ of three-times upsetting and three-times stretching with broadening by upsetting were simulated by Deform-3D. The results ofsimulation show that the equivalent strains in simulated forgings by the schemeⅢ and Ⅳ are8.99and12.0respectively. The forging ratio of the scheme Ⅰ isgreater about4.04than that of the scheme Ⅳ. The value of equivalent strains bythe scheme Ⅲ is greater3.01than that by the scheme Ⅳ.4. The simulation and experiment results of the scheme Ⅱ and the schemeⅣ with different broadening operation have been compared. It shows that theequivalent strain in forgings by the scheme Ⅳ with the upsetting broadeningoperation is greater0.9than that of in forgings by the scheme Ⅱ with thedrawing broadening operation, when there is one more drawing operation in thescheme Ⅱ. Experiment results show that microstructure in the forgings by thescheme Ⅳ is more homogeneous and refined; Second phases is more refineddispersed; properties are better, especially the plastic indexes, those values arecloser in the three perpendicular directions. Therefore, the process ofthree-times upsetting and three-times stretching with the upsetting broadening isbetter than that of four-times upsetting and three-times stretching with thedrawing broadening.