Prediction of Hardness of Aluminum Alloy 7055 by Quench Factor Analysis

Abstract

The Vickers hardness time-temperature-properties (TTP) curve of aluminum alloy 7055 was evaluated by interrupted quench technique. The critical temperature range of TTP curve was determined from 210 °C to 420 °C with the nose temperature of 355 °C. The hardness decreased rapidly with isothermal duration in the critical temperature range. The hardness of aluminum alloy 7055 was predicted by quench factor analysis using the TTP curve and cooling curves. The predicted hardness agreed reasonably well with the measured results. The influence of time step and summation temperature range on the predicted results was studied. The cooling rate through the critical temperature range had dominant influence on the final hardness of the alloy.

Precipitation Kinetics Analysis of the Cooling Process Following the Solid Solution Treatment of 7B50 Aluminum Alloy

“…The time interval ∆t in Eq. 7 is selected to ensure that the temperature decreasing in each time interval is less than 25℃ [5,27]. The partial continuous cooling curves located in the quench sensitive temperature range of 7B50 alloy (420 ℃ ~230 ℃ ) are averagely partitioned by an appropriate time interval ∆t.…”

“…The 7XXX series ultra-high-strength aluminum alloys are extensively used in the aerospace industry due to their desirable specific mechanical properties [1][2][3]. With the thickness of plates increasing [4], the cooling rates are gradually nonuniform along their thickness direction, which leads to the properties inconsistent between the surfaces and center parts of them [3,5]. Therefore, it is significant to predict the properties along the thickness direction of 7XXX series alloys thick plates.…”

Research on microstructure in as-cast 7A55 aluminum alloy and its evolution during homogenization

“…It is well known that the AA 7055-T7751 in plate form offers an increase in strength of 10% and 30% relative to that of 7150-T6 and 7150-T76, respectively [4]. Due to its significance in engineering applications, many investigations have been conducted on the solution treatment [1,[5][6], aging process [4,[7][8][9] and quench sensitivity [10][11][12] of high strength 7055 aluminum alloys. The homogenization process is applied in practical production for high alloying elements content 7000, however, the study on microstructure in as-cast 7A55 aluminum alloy and its evolution during homogenization is still very limited [13][14].…”