(南京航空航天大學(xué) 機(jī)電學(xué)院，南京 210016)
摘 要: 針對傳統(tǒng)多層空心整體結(jié)構(gòu)在超塑成形/擴(kuò)散連接(SPF/DB)工藝過程中存在的中心夾層焊接可靠性差的關(guān)鍵工藝問題，以某飛行器TC4(T-6Al-4V)鈦合金舵體四層空心復(fù)合整體結(jié)構(gòu)為對象，提出了激光預(yù)焊芯板夾層的超塑成形/擴(kuò)散連接新工藝。基于有限元軟件模擬仿真分析及相應(yīng)的試驗研究，采用激光預(yù)焊芯板夾層的SPF/DB先進(jìn)工藝，進(jìn)行某飛行器TC4鈦合金四層空心復(fù)合整體舵體零件的研制。結(jié)果表明：運(yùn)用SPF/DB新工藝，在920 ℃、真空度為5×10-3 Pa、最大氣壓壓力為1.2 MPa 條件下超塑成形/擴(kuò)散連接成形出合格的舵體零件，其焊合率達(dá)95%以上，壁厚分布均勻性大于90%，晶粒尺寸長大控制在35%以內(nèi)。
關(guān)鍵字: TC4鈦合金；激光焊接；超塑成形；擴(kuò)散連接；有限元模擬；舵體
（College of Mechanical and Electrical Engineering,
Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China）
Abstract:In view of the traditional multilayer hollow structure superplastic forming and diffusion bonding (SPF/DB) process which leads to a poor reliability of welding core interlayer, a new method based on laser pre-welding for core layers was raised up for the aircraft rudder of four TC4 (Ti-6Al-4V) titanium alloy layers with composite hollow structure. With the experimental study and corresponding finite element simulation analysis carried out, a forming method of the four layers aircraft rudder body part was developed based on the new SPF/DB process of laser pre-welding core sheets. The results show that: adopting the new SPF/DB technology under the conditions that at the temperature of 920 ℃, vacuum degree of 5×10-3 Pa, and the maximum pressure of 1.2 MPa, the rudder body part is qualified reaching a welding rate above 95% and wall thickness distribution uniformity greater than 90%,and controlling the grain size growth in 35%.
Key words: TC4 titanium alloy; laser welding; superplastic forming; diffusion bonding; finite element simulation; rudder
