大型双曲率非等厚TC4钛合金壁板整体SPF/DB成形工艺及优化  

Integral SPF/DB forming process and its optimization for TC4 titanium alloy panel with large size, dual curvature and non-uniform thickness

作　　者：王会东 付和国 韩颖杰[1] 谢洪志[1] 张鑫[1] 尹延广 赵天章[2] Wang Huidong;Fu Heguo;Han Yingjie;Xie Hongzhi;Zhang Xin;Yin Yanguang;Zhao Tianzhang(Shenyang Aircraft Corporation,Shenyang 110034,China;School of Aerospace and Engineering,Shenyang Aerospace University,Shenyang 110136,China)

机构地区：[1]沈阳飞机工业(集团)有限公司,辽宁沈阳110034 [2]沈阳航空航天大学航空宇航学院,辽宁沈阳110136

出　　处：《锻压技术》2022年第1期75-80,共6页Forging & Stamping Technology

摘　　要：针对大型双曲率非等厚TC4钛合金壁板整体SPF/DB成形工艺进行了研究。由于零件尺寸超过1800 mm,型面复杂(双曲率,弦高为330 mm),壁厚分布不均匀,成形后出现了严重开裂(多于6处)、明显缩沟(深度大于1.1 mm)和不贴模等缺陷,且在成形后难于通过化铣精确控制壁厚分布,提出了预变形、化铣、扩散连接和超塑成形的新工艺思路,通过有限元模拟预测了超塑成形后的壁厚分布,验证先化铣再SPF/DB的工艺路线的可行性。并利用自动敷膜和激光刻形等手段提高了隔离剂的涂覆精度,最终在870~930℃、1.0~1.5 MPa的条件下成功整体超塑成形得到壁板零件,并且表面无阶差和缩沟等缺陷,贴模度小于0.3 mm,焊合率超过90%,壁厚分布较为均匀,在口框交叉位置的减薄最为严重,约为母材原始厚度(2 mm)的44.5%,达到了该零件的关键技术指标。The integral SPF/DB(Super Plastic Forming/Diffusion Bonding) forming process for TC4 titanium alloy panel with large size, dual curvature and non-uniform thickness was investigated, the forming defects including serious fracture(more than six places), obvious shrinkage of grooves(depth of more than 1.1 mm) and badly die attaching appeared after forming due to part size exceeding 1800 mm, complex profile(double curvature, chord height of 330 mm) and uneven wall thickness, and it was difficult to precisely control the distribution of wall thickness after forming by the chemical milling. Therefore, a new process of pre-deformation, chemical milling, diffusion bonding and superplastic forming was proposed, the distribution of wall thickness after superplastic forming was predicted by the FEM simulation, and the feasibility of the process route for chemical milling first and then SPF/DB was proved. Furthermore, the coating accuracy of release agent was improved by the automatic film coating and laser engraving, the panel parts were finally successfully obtained by integral superplastic forming under the condition of 870-930 ℃、1.0-1.5 MPa without defects such as step difference and shrinkage grooves on the surface, the degree of die attaching was smaller than 0.3 mm, the welding rate was more than 90%, the wall thickness distribution was relatively uniform, and the thinning at the intersection of mouth frame was most serious, which was 44.5% of the origin thickness(2 mm). Thus, the main technical requirements of the part were achieved.

关 键 词：SPF/DB 钛合金 壁板 双曲率 壁厚 

分 类 号：TG146.23[一般工业技术—材料科学与工程]