(1. 青島理工大學(xué) 機(jī)械與汽車工程學(xué)院，青島 266520；
2. 哈爾濱工業(yè)大學(xué) 先進(jìn)焊接及連接國(guó)家重點(diǎn)實(shí)驗(yàn)室，哈爾濱 150001)
摘 要: 采用Ni/Al/Zn復(fù)合釬料層對(duì)AZ31和2024合金實(shí)現(xiàn)了大氣環(huán)境下、無釬劑的超聲輔助瞬間液相擴(kuò)散連接(U-TLP)，研究采用Ni層、Ni/Zn層、Zn/Ni/Zn層及Al/Zn/Ni/Zn層時(shí)釬縫的微觀組織及接頭的力學(xué)性能，分析Ni箔、Al箔及Zn箔在U-TLP過程中的作用。結(jié)果表明：通過調(diào)整Ni/Al/Zn復(fù)合釬料層的組合形式，可以實(shí)現(xiàn)對(duì)釬縫微觀組織的調(diào)控及力學(xué)性能的改善，采用Al/Zn/Ni/Zn復(fù)合釬料層時(shí)釬縫剪切強(qiáng)度達(dá)到最高值(95.3 MPa)。Ni箔起到了“物理屏障”的作用，阻礙了Mg-Al金屬間化合物(IMCs)的形成，但是由于鋁合金一側(cè)釬縫僅由Al3Ni組成，接頭剪切強(qiáng)度僅為21.2 MPa。Zn箔的添加促進(jìn)鋁母材溶解，增加Al3Ni的數(shù)量并形成Zn-Al共晶，提高2024合金一側(cè)的連接強(qiáng)度。Al箔的填入降低AZ31合金的溶蝕，并在鎂合金側(cè)形成MgZn2、MgZn和含有Mg2Ni、Al3Ni、AlMg4Zn11和NiZn8的混合IMCs層的組織，提高AZ31合金與Ni箔的連接。
關(guān)鍵字: Ni/Al/Zn復(fù)合釬料層；AZ31/2024；異種金屬釬焊接頭；超聲；瞬間液相擴(kuò)散焊；復(fù)合釬料層；力學(xué)性能
（1. School of Mechanical and Automotive Engineering, Qingdao University of Technology, Qingdao 266520, China;
2. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China）
Abstract:By using the Ni/Al/Zn multi-interlayers, the high mechanical performance AZ31/2024 dissimilar alloys joints were made via ultrasonic-assisted transient liquid phase bonding (U-TLP) in air without any fluxes. The microstructure and mechanical performance of the joints were researched by using different set-up of multi-interlayers such as Ni, Ni/Zn, Zn/Ni/Zn and Al/Zn/Ni/Zn. The function of the Ni, Al and Zn foil acted during U-TLP was analyzed. The results show that the phases in the joints can be controlled and mechanical performance of the joints can be improved by adjusting the set-up of the multi-interlayers. The Al/Zn/Ni/Zn interlayers combination significantly increases the shear strength up to 95.3 MPa. The Ni foil, which acts as “physical barrier”, prohibits the formation of Mg-Al intermetallic compounds, however, the shear strength is only 21.2 MPa, which is caused by that the joints at 2024 alloys side is only composed of Al3Ni. The Zn foil accelerates the dissolution of Al atom and increases the amount of Al3Ni. In addition, Zn-Al eutectics are formed and improve the joining between the Ni foil and 2024 alloys. The Al foil, whose aim is to slow down the dissolution of AZ31 alloys, helps to form a IMCs layer of mixture that is composed of Mg2Ni, Al3Ni, AlMg4Zn11 and NiZn8 along the Ni foil and enhance the bonding between Ni foil and AZ31.
Key words: Ni/Al/Zn multi-interlayer; AZ31/2024; dissimilar alloy brazing joints; ultrasonic; transient liquid phase bonding; multi-interlayer; mechanical performance
