文中针对航空发动机风扇及压气机盘TC17钛合金材料,开展了接头组织分析、拉伸性能测试及硬度测试,分析了接头不同部位组织特征及形成原因.结果表明,接头明显分为母材区(BM)、热力影响区(TMAZ)和焊合区(WZ),焊接接头中部热力影响区的组织表现为等轴晶粒,而靠近焊缝边缘处热力影响区的晶粒表现为沿着受力方向被拉长,焊合区发生了动态再结晶;接头的拉伸性能与母材相当;接头热力影响区的硬度高于母材和焊合区,平均硬度为486 HV.

随着航空发动机性能的不断提高，高推重比发动机要求减轻结构重量，降低研制和制造成本，这对制造技术提出了更加苛刻的要求，常规的连接技术已经不能满足发动机高推比、长寿命、低成本的要求。而摩擦焊因具有焊缝质量高、无烟尘和飞溅、无需填充材料和气体保护、材料损耗少、焊缝缺陷少等优点，成为航空发动机研制中的关键技术之一。线性摩擦焊、惯性摩擦焊分别在航空发动机整体叶盘和转子鼓筒的制造中具有独特的技术优势。

<正>整体叶盘(环)已经作为新型航空发动机的重大改进部件,不仅应用于在研型号,而且还将在未来高推重比发动机上广泛应用。整体叶盘的制造将更依赖于数控机床的发展、依赖于线性摩擦焊技术及装备的发展以及电解加工技术的发展,真正实现优质、高效、低成本制造。

近20年来,随着焊接技术的研究和应用水平的进步,特别是在材料的焊接性能研究、自动化焊接工艺方法和工艺技术、结构的焊接应力变形控制以及焊接接头力学性能和可靠性等方面的研究深入和水平提高,在"合于使用"的先进设计理念的引领下,钛合金焊接结构越来越广泛地应用到飞机的重要承力结构上.事实上飞机重要承力件采用钛合金焊接结构的技术优势,在20世纪七八十年代前苏联研制的第3代军用飞机上即得到了很好的印证,并引起了欧美航空制造界的高度重视.越来越多的资料报道表明,欧美航空制造业已经将钛合金焊接结构从飞机的次承力结构应用到主承力结构上[1].

Penetration welding is an important welding type in titanium thin sheet structures. Based on the analysis about welding parameter,weld shape,porosity,weld microstructure,tensile property、bending property,and gas amount,the influence of the A-TIG technique on penetration welding joint of the TA15 titanium alloy was investigated,also the contrast between penetration weld and butt weld was investigated. The results show that the A-TIG technique could make the similar influence on such respects as welding parameter,weld shape,porosity,weld microstructure,and gas amount to the both penetration weld and butt weld,also the similar influences of A-TIG on the tensile property、bending property to the penetration welding and the butt weld.

In this paper,the effects of different kinds of activating fluxes on appearance of weld was analysed during the electron beam welding(EBW)of nickel-base super alloy GH4169,oxides had deep influence on welding depth and weld formation of both sides of plate,while fluoride had no influence.And on base of it,activating fluxes which can greatly improve weld shape and surface quality of EBW are obtained by combination and optimization.The reason of improving appearane of weld is that,with activating fluxes change surface tension gradient in the weld pool,then affect the pattern of the fluid flow,consequently form narrow and deep,well shape weld.The results show that activating electron beam welding can improve appearane of weld and eliminate some surface defects such as undercutting,which is very useful during thin plate EBW.

与常规TIG焊接工艺相比,钛合金A-TIG焊接电弧的穿透能力显著增强,热输入量、焊接变形及应力减小。焊接相同规格的产品构件时,在相同的焊接电流条件下,可以实现不开坡口单道焊接或使堆焊层数明显减少,从而提高焊接生产率和产品质量,成倍降低成本。

TIG welding process of BT20 Ti alloy with single active flux CaF2 is investigated and compared with conventional TIG welding process of BT20. The partial spectrum in A-TIG welding process is tested by spectrometer. The distribution law of flux element in arc space and the effect of flux on argon element distribution in different arc area are analyzed.

TIG(tungsten inert-gas) welding processes and A-TIG(A activating) processes of TC4 titanium alloy with FT-01 activating flux made in BAMTRI were investigated. The crystal structure of two kinds of welds was compared, and the chemical composition of the welds were tested. The results showed that the activating flux has a visible influence on the crystal structure of welds, but has no relationship with the composition of the welds.

BT20 titanium alloy of 2.5mm thickness was welded by conventional TIG and single-component fluoride flux TIG,respectively.The results showed that the influences of different single-component fluorides on the shape of arc are different.And the relationship of arc shape and the weld penetration was also obtained.

对厚2.5 mm的BT20钛合金平板,沿不同氟化物焊剂进行TIG焊接(A-TIG),并与相同规范下的常规TIG焊进行对比,试验证明,不同的单组分氟化物焊剂对焊缝成形、熔透深度的影响有较大差别.文中分析了A-TIG焊得到的焊接接头的金相组织.

:A 1Cr18Ni9Ti stainless steel is welded by A-TIG welding with activating flux Cr(2)O(3 ).By altering the welding parameters, the effects of welding current,welding velocity and arc length on weld penetration and weld width are studied.The results show that in the case of 1 mm, arc length the activating flux remarkably increases weld penetration and decreases weld width when the welding current is over 80 A.The flux can increase weld penetration and decrease weld width prominently when the arc length is less than 1.5 mm.The flux reduces the variation of weld penetration and weld width with that of welding velocity slow.

采用自制的钛合金活性焊剂FT-01进行焊接工艺试验,对焊接过程中焊缝形貌的影响进行了对比分析.所得试验结果为活性焊剂焊接过程中焊缝形貌特点的机理分析奠定了试验基础.