(1. 西安交通大學(xué) 金屬材料強(qiáng)度國(guó)家重點(diǎn)實(shí)驗(yàn)室，西安 710049；
2. 哈爾濱工業(yè)大學(xué) 先進(jìn)焊接與連接國(guó)家重點(diǎn)實(shí)驗(yàn)室，哈爾濱 150001)
摘 要: 為表征降熔元素Zn在鋁基復(fù)合材料釬焊中的擴(kuò)散行為及其對(duì)去膜效果的影響，并改善Zn基釬料的潤(rùn)濕性(添加活性元素Li)，用坐滴法在520 ℃、10~30 min、5 L/min流動(dòng)Ar保護(hù)條件下測(cè)試純Zn、Zn-5Al二元共晶、自制Zn-6Al-1Li三元共晶、自制Zn-21Al-3Li三元包共晶共4種釬料對(duì)SiCp/ZL101鋁基復(fù)合材料的潤(rùn)濕性。結(jié)果表明：對(duì)于無Li的Zn基釬料，隨保溫時(shí)間的延長(zhǎng)，Zn僅在局部范圍可沿晶界擴(kuò)散入Al基體，出現(xiàn)晶界液化甚至溶蝕，但難以出現(xiàn)晶粒液化，釬料/母材界面間隙依然難以消除；對(duì)于含Li活性釬料，Li的適度添加(約3%，質(zhì)量分?jǐn)?shù))使得Zn的滲入在整個(gè)界面趨于均勻分布，消除了局部溶蝕與界面空隙，對(duì)潤(rùn)濕性有良好改善效果；Zn的滲入引起大量尺寸約為10 μm的(Si)塊在界面析出。
關(guān)鍵字: 鋁基復(fù)合材料；無釬劑釬焊；自釬劑釬料；晶界滲透；溶蝕；膜下溶解
（1. State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China;
2. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China）
Abstract:In order to characterize the diffusion behavior of Zn as melting point depressant (MPD) and its potential ability on removing oxide film during the brazing of aluminum matrix composite and improve the wettability of Zn based filler metals by adding active element of Li, the wettability of pure Zn, Zn-5Al eutectic, the developed Zn-6Al-1Li ternary eutectic and Zn-21Al-3Li ternary quasi-eutectic on the aluminum metal matrix composite of SiCp/ZL101 were tested with sessile drop method at 520 ℃ for 10−30 min within flowing argon (5 L/min) atmosphere. The results and that, for the Zn-base filler metal without lithium, with increasing the soaking time, the Zn atoms only penetrated into the matrix in local area only along the grain boundary, resulting in the dissolution of the grain boundary and even local erosion, but the grain dissolution can not occur, and the gap between the matrix and residual filler metal is obvious. For the active filler metal with lithium at a moderate level of about 3% (mass fraction), Zn can uniformly diffuse into the matrix along grain boundary on the whole surface of the matrix covered by the filler, eliminating the local erosion and the interface gap, and hence improving the wettability on the composite. The diffusion of Zn into the matrix of ZL101 causes the precipitation of lots of silicon particles of about 10 μm along the interface.
Key words: aluminum metal matrix composite; fluxless brazing; self-flux brazing alloy; grain boundary penetration; erosion; undermining
