2024铝合金件精密等温锻造工艺研究

Study on isothermal forging process of 2024 aluminum alloy precision parts

用H13热作模具钢制作了等温锻造模具,并采用等温锻造工艺对大型2024铝合金锻件挤压成形。先将铝合金板材预锻成预制坯,然后用20 MN液压机进行等温锻造。等温锻造工艺中,模具温度为(450±10)℃,2024铝合金预制坯温度为(465±10)℃,成形时最大挤压力为11000 kN。等温锻造试验表明,等温锻造模具采用渗氧氮化热处理工艺后,可以提高模具的抗黏附性。在试制过程中,对等温锻造模具侧板圆角半径进行优化,比较R5,R10和R15 mm这3种圆角半径,测试后发现圆角半径为R15 mm的模具侧板可以更好地改善金属流动性,并减缓锻件与模具的粘结。此外,比较了两种等温锻造工艺,结果表明,通过预锻或第1道次终锻出现筋条大圆角,可以保证终锻后筋条充满。

The large 2024 aluminum alloy precision part was produced with isothermal forging process by isothermal forging die made by hot die steel H13. The perform was produced from aluminum plate, then it was isothermal forged in 20 MN hydraulic press. The tempera- ture of die was （450 ~ 10） ~C , the temperature of 2024 aluminum alloy perform was （465 ~ 10） ~C , and the highest forming force was 11000 kN. The isothermal forging experiment shows that the anti-adhesion performance of die can be improved after nitrogen oxide treat- ment on the forging die. In addition, three types of fillet radius RS, R10 and R15 mm of the isothermal forging tool side plate were tested and compared during the forging process, and the results show that the tool side plate with R15 mm fillet radius can improve the flow abili- ty of the metal and reduce the adhesion between die and perform. Furthermore, two isothermal forging processes were analyzed and the re- sult shows that the gusset can be filled well after performing or big fillet radius made by the first step forging.