Analysis of local loading forming for titanium-alloy T-shaped components using slab method

Int J Adv Manuf Technol

Fan

et al. 2014

The forming quality of transitional region plays a key role in the performance of titanium alloy large-scale ribweb component under isothermal local loading forming. In this work, a local eigen model of transitional region in the local loading forming of large-scale rib-web component is extracted so as to catch the detail-forming characteristics of transitional region with low computation time in simulation and experiment cost. Then, based on the local eigen model, the mechanism of forming defects in transitional region and their dependence on processing parameters are studied by the combination of physical experiment and verified finite element (FE) simulation. It is found that the second loading step can be divided into two forming stages according to the material flow pattern: (1) the transverse flow stage and (2) the stable forming stage. In the transverse flow stage, there exists long-range transverse flow of web material and excessive transverse flow would lead to the formation of folding and cavum defects. Moreover, the severities of defects are well correlated with the quantity of material transferred into the first-loading region in this stage. For a certain reduction amount, decreasing spacer block thickness and increasing friction both can decrease the quantity of transferred material and then suppress the development of folding and cavum defects, while the deformation temperature and loading speed have little effect on the quantity of transferred material and defects. In the end, an effective way is put forward to suppress and prevent the defects in transitional region during the local loading forming of titanium alloy large-scale rib-web component.

Section: Physical Experiments and Its Fe Simulationmentioning

confidence: 99%

“…The lead used here is in forging state and its flow behavior has been obtained based on compression test by our group in Zhang et al [15] as follows:…”

Section: Physical Experiments and Its Fe Simulationmentioning

confidence: 99%

Forming defects control in transitional region during isothermal local loading of Ti-alloy rib-web component

Gao

Int J Adv Manuf Technol

Fan

et al. 2014

“…However, the coordination of uneven deformation and the control of microstructure under multi-pass high temperature deformation should be solved before the local loading comes to industrial application. Therefore, the deformation behavior and uneven deformation mechanism in local loading forming of rib-web component were revealed through the combination of theoretical analysis, numerical simulation and experiments [113,114]. The effects of local loading method and local loading parameters on the forming process and forming quality were analyzed [115,116].…”

Section: Near Net Shape Forming Of Large-scale Complex Components Witmentioning

confidence: 99%

Recent developments in plastic forming technology of titanium alloys

Sci. China Technol. Sci.

Fan

Sun

et al. 2011

Titanium alloys have been used extensively in industry fields including aviation, aerospace and automobile due to their excellent comprehensive properties. Research and development of advanced plastic forming technology are of great importance to manufacturing titanium products of high performance and lightweight with low cost and short cycle. This paper analyzes the development tendencies of titanium alloy forming technology. Recent achievements in precision forming, microstructure control and multi-scale simulation of titanium alloys are reviewed. The forming techniques of large-sale integral complex components are presented. titanium alloys, precision forming, microstructure control, multi-scale simulation, large-scale integral complex components Citation:Yang H, Fan X G, Sun Z C, et al. Recent developments in plastic forming technology of titanium alloys.

“…In the local loading process of TA15 titanium alloy bulkhead presented in Section 3.2, the loading speed is about 0.2 mm/s. In the isothermal local loading processes of eigenstructures which are put forward from large-scale components and can reflect the forming characteristics of large-scale components, the speed of upper die may come up to 1 mm/s [25]. Sun and Yang [26] presented the optimal forging technique of titanium alloy in multifire forging as follows: adopting conventional forging at first and then following near-beta forging.…”

Section: Experimental Conditionsmentioning

confidence: 99%

Friction factor evaluation by FEM and experiment for TA15 titanium alloy in isothermal forming process

Zhang

Int J Adv Manuf Technol

et al. 2011

The friction at die-workpiece interface is an important parameter in metal forming processes, which affects the metal flow, cavity fill, surface quality, etc. The friction in the forming process is influenced by material properties and forming conditions. The friction in forming process of TA15 (Ti-6Al-2Zr-1Mo-1V) titanium alloy under high temperatures (isothermal forming) and low strain rates is studied here by ring compression test. The friction calibration curves are elaborated by means of finite element method. The research on the calibration curves and friction factor at the loading speed v=0.1-1.0 mm/s and the conventional forging temperature (950°C) and near-beta forging temperature (970°C) is carried out. The influence of loading speed on friction calibration curves is similar to the influence on friction factor m: at the low (m about 0.7) friction condition, the influence of loading speed can be ignored, however the influence is notable in the midst magnitude (about 0.2-0.5). The temperature variation from 950°C to 970°C has little influence on friction calibration curves, but has notable influence on m under lubricated condition.