陈勇 郑智斌 靳德民 李雪 陈俊宏

摘要： 利用座滴法在高真空条件下研究了Cu-Al和Al-Mg合金分别在1 100～1 200 ℃，700～800 ℃与304不锈钢的润湿行为。研究表明，铜-钢体系为典型的溶解润湿，铝-钢体系为典型的反应润湿，且最终润湿性随着温度的升高而改善;铜-钢体系中，钢表面的氧化膜限制固-液界面传质从而导致差的润湿性，破除氧化膜及Fe在Cu中的扩散作用为熔滴铺展提供驱动力，铺展活化能为51.2 kJ/mol，该活化能对应于Fe在Cu中的扩散激活能（约10 kJ/mol）及破除氧化膜后表面由Fe-O氧化膜转变为纯净Fe时，Fe和Fe3O4单位摩尔表面能的变化（44.9 kJ/mol）;铝-钢体系中，前驱膜的产生能够有效促进润湿，前驱膜为界面反应层在三相线外的延伸;铺展动力学可由RPC模型描述，铺展活化能为46.6 kJ/mol，该活化能对应于界面反应生成单位摩尔的Fe2Al5（约25 kJ/mol）及FeAl3（约21 kJ/mol）的反应吉布斯自由能。

关键词： 反应润濕; 扩散润湿; 前驱膜; 界面行为; 304不锈钢

中图分类号： TG 401

Dissolutive versus reactive wetting on surface of 304 stainless steel by molten Cu-Al and Al-Si-Mg alloy

Chen Yong1， Zheng Zhibin2， Jin Demin2， Li Xue2，Chen Junhong2

（1. China Railway Rail Materials Group Corporation， Beijing 100000， China; 2. Gansu Vocational & Technical College of Nonferrous Metallurgy， Jinchang 737100， Gansu， China）

Abstract： Wetting of 304 stainless steel by two industrial grade Al-Mg alloy and Cu-Al alloys were studied by modified sessile drop method at 1 100～1 200 ℃， 700～800 ℃， respectively.Cu/steel system was typically dissolve wetting and the Al/steel system was typically reactive wetting， the wetting behavior gradually was improved with the temperature rising. In Cu/steel system， the Fe-O oxide film on surface of substrate was the crucial factor， which could be deteriorate wetting， removing the oxide film and diffusion of Fe in liquid might mainly contribute may to the spreading forces. The wetting activation energy was 51.2 kJ/mol， which was corresponding to diffusion activation energy for Fe in the liquid Cu （～10 kJ/mol） and different per molar area surface energies between Fe and Fe-O oxide film （44.9 kJ/mol）. In Al/steel system， precursor film could significantly promote wetting and the formation mechanism was “subcutaneous penetration”. Wetting systems could be described by RPC model and the wetting activation energy was 46.6 kJ/mol，which was corresponding to the Gibbs free energy for the Fe2Al5（25 kJ/mol）and FeAl3（21 kJ/mol）.

Key words： reactive wetting; diffusion wetting; precursor film; surface behavior; 304 stainless steel

0 前言304不锈钢因其高强度及热稳定性好等优势而被广泛应用于核电主管道、汽车工业及航空航天框架结构材料[1-4]。然而，为满足国家节能减排及低碳的战略需求，汽车轻量化材料及高热导高强材料是目前核电及汽车工业急需的结构材料。因此，铝-钢复合结构和铜-钢复合结构在汽车轻量化及提高核电热交换领域具有广泛的应用前景。然而，在铜-钢及铝-钢连接过程中接头成形差及界面脆性化合物的生成是导致接头性能低的关键因素[5-6]。Sun等人[7]在研究钛-钢CMT连接中通过采用铜中间层来抑制Ti-Fe金属间化合物的产生，从而提高接头强度，而铜在钢表面差的润湿性导致接头成形变差，从而导致接头性能差。……