工程科学学报.第42卷，第12期：1631-1638.2020年12月 Chinese Journal of Engineering,Vol.42,No.12:1631-1638,December 2020 https://doi.org/10.13374/j.issn2095-9389.2019.12.11.004;http://cje.ustb.edu.cn 7075铝合金板材热冲压成形中的高温摩擦 吴佳松，蒋怡涵，王武荣四，韦习成 上海大学材料科学与工程学院.上海200072 ☒通信作者，E-mail:wrwang @shu.edu.cn 摘要采用自制的板带高温摩擦试验机模拟实际固溶-冲压-淬火一体化热成形工艺下7075铝合金的高温摩擦过程，分别 对上下摩擦头进行冷却和加热以模拟实际热冲压过程对模具和压边圈的冷却和加热，分析了下模加热温度、法向载荷和滑 动速度对7075铝合金摩擦行为及磨损机理的影响.结果表明：铝合金摩擦系数随着下模加热温度的升高而增大，磨损机制 由300℃时的黏着磨损转变为500℃时的黏着磨损、氧化磨损和磨粒磨损：施加法向载荷越大，摩擦系数越大，不同载荷下 磨损机制均为黏着磨损及轻微的磨粒磨损，且随着载荷增大，黏着磨损程度有所加深：高滑动速度导致了磨损表面局部氧化 物的生成，使摩擦系数随着滑动速度增大而减小，滑动速度为30s时，磨损机制主要是氧化磨损、磨粒磨损和黏着磨损. 关键词热冲压：7075铝合金：高温摩擦：摩擦系数：磨损机制 分类号TG115.5 High-temperature friction of 7075 aluminum alloy sheet during hot stamping WU Jia-song,JIANG Yi-han,WANG Wu-rong,WEI Xi-cheng School of Materials Science and Engineering,Shanghai University,Shanghai 200072,China Corresponding author,E-mail:wrwang @shu.edu.cn ABSTRACT Aluminum alloys are lightweight materials widely used in the automobile industry because of their high specific strength. As the aluminum alloy with the highest strength at room temperature,7075 aluminum alloy has great potential for usage in the manufacturing of structural parts.However,its formability at room temperature is poor and its springback is large.Although both good formability and high strength in aluminum alloys can be realized by hot forming,7075 aluminum alloy has high susceptibility to adhesive wear,which means its tribological properties are poor during hot forming.Exploration of the influence of process parameters on the friction behavior and wear mechanism of 7075 aluminum alloy has great significance for the numerical simulation of the hot- stamping process and lubrication engineering.The high-temperature friction process of 7075 aluminum alloy during the actual hot forming-quenching integrated process was simulated by a self-made high-temperature strip friction tester.The upper and lower friction components were cooled and heated,respectively,to simulate the cooling and heating of the die(blank holder)in the actual hot-stamping process.The effects of the preheating temperature of the lower die,normal load,and sliding speed on the friction behavior and wear mechanism of 7075 aluminum alloy were analyzed.The results show that the friction coefficient of aluminum alloy increases with increase in the preheating temperature,and the wear mechanism changes from adhesive wear at 300 C to adhesive,abrasive,and oxidative wear at 500 C.The larger the normal load applied,the larger is the friction coefficient.The wear mechanism under different loads was determined to be adhesive wear with slight abrasive wear,with the degree of adhesive wear increasing with the increase in load.A high sliding speed leads to the formation of local oxides on the surface,which makes the friction coefficient decrease with an increase in the sliding speed.The main wear mechanisms are oxidative,abrasive,and adhesive wear when the sliding speed is 30 mm-s- 收稿日期：2019-12-11 基金项目：国家自然科学基金资助项目(51475280)7075 铝合金板材热冲压成形中的高温摩擦 吴佳松，蒋怡涵，王武荣苣，韦习成 上海大学材料科学与工程学院，上海 200072 苣通信作者，E-mail: wrwang@shu.edu.cn 摘    要    采用自制的板带高温摩擦试验机模拟实际固溶–冲压–淬火一体化热成形工艺下 7075 铝合金的高温摩擦过程，分别 对上下摩擦头进行冷却和加热以模拟实际热冲压过程对模具和压边圈的冷却和加热，分析了下模加热温度、法向载荷和滑 动速度对 7075 铝合金摩擦行为及磨损机理的影响. 结果表明：铝合金摩擦系数随着下模加热温度的升高而增大，磨损机制 由 300 ℃ 时的黏着磨损转变为 500 ℃ 时的黏着磨损、氧化磨损和磨粒磨损；施加法向载荷越大，摩擦系数越大，不同载荷下 磨损机制均为黏着磨损及轻微的磨粒磨损，且随着载荷增大，黏着磨损程度有所加深；高滑动速度导致了磨损表面局部氧化 物的生成，使摩擦系数随着滑动速度增大而减小，滑动速度为 30 mm·s−1 时，磨损机制主要是氧化磨损、磨粒磨损和黏着磨损. 关键词    热冲压；7075 铝合金；高温摩擦；摩擦系数；磨损机制 分类号    TG115.5 High-temperature friction of 7075 aluminum alloy sheet during hot stamping WU Jia-song，JIANG Yi-han，WANG Wu-rong苣 ，WEI Xi-cheng School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China 苣 Corresponding author, E-mail: wrwang@shu.edu.cn ABSTRACT    Aluminum alloys are lightweight materials widely used in the automobile industry because of their high specific strength. As the aluminum alloy with the highest strength at room temperature, 7075 aluminum alloy has great potential for usage in the manufacturing of structural parts. However, its formability at room temperature is poor and its springback is large. Although both good formability and high strength in aluminum alloys can be realized by hot forming, 7075 aluminum alloy has high susceptibility to adhesive wear, which means its tribological properties are poor during hot forming. Exploration of the influence of process parameters on the friction behavior and wear mechanism of 7075 aluminum alloy has great significance for the numerical simulation of the hot￾stamping process and lubrication engineering. The high-temperature friction process of 7075 aluminum alloy during the actual hot forming–quenching integrated process was simulated by a self-made high-temperature strip friction tester. The upper and lower friction components were cooled and heated, respectively, to simulate the cooling and heating of the die (blank holder) in the actual hot-stamping process. The effects of the preheating temperature of the lower die, normal load, and sliding speed on the friction behavior and wear mechanism of 7075 aluminum alloy were analyzed. The results show that the friction coefficient of aluminum alloy increases with increase in the preheating temperature, and the wear mechanism changes from adhesive wear at 300 °C to adhesive, abrasive, and oxidative wear at 500 °C. The larger the normal load applied, the larger is the friction coefficient. The wear mechanism under different loads was determined to be adhesive wear with slight abrasive wear, with the degree of adhesive wear increasing with the increase in load. A high sliding speed leads to the formation of local oxides on the surface, which makes the friction coefficient decrease with an increase in the sliding speed. The main wear mechanisms are oxidative, abrasive, and adhesive wear when the sliding speed is 30 mm·s−1 . 收稿日期: 2019−12−11 基金项目: 国家自然科学基金资助项目（51475280） 工程科学学报，第 42 卷，第 12 期：1631−1638，2020 年 12 月 Chinese Journal of Engineering, Vol. 42, No. 12: 1631−1638, December 2020 https://doi.org/10.13374/j.issn2095-9389.2019.12.11.004; http://cje.ustb.edu.cn