退火热处理对低压冷喷涂Cu-Zn复合涂层性能的影响

Effect of Annealing Heat Treatment on Properties of Low-pressure Cold Sprayed Cu-Zn Composite Coatings

摘要:

以 Cu-Zn混合粉末作为喷涂粉体,采用低压冷喷涂技术在1Cr13基体上制备Cu-Zn复合涂层,在不同退火温度下对复合涂层进行退火热处理,然后测试涂层的力学性能。利用X射线衍射仪、场发射扫描电子显微镜、显微硬度仪等设备对退火热处理前后复合涂层进行微观形貌观察和硬度测试。结果表明：铜锌复合涂层结构致密,涂层与基体结合紧密；铜锌复合涂层在200℃~300℃间退火时,涂层中金属颗粒间界面明显,涂层内部形成β(CuZn)、γ(Cu₅Zn₈)等金属间化合物。退火温度为200℃时,铜锌复合涂层的硬度达到最高(157.8HV_0.2),结合强度达到最低(7.5MPa)；铜锌复合涂层在350℃~450℃间退火时,涂层中金属颗粒间部分界面不明显；当退火温度为450℃时,铜锌复合涂层硬度达到最低(102.4HV_0.2),结合强度达到最高(13.9MPa)。

Abstract:

Using Cu-Zn mixed powder as spray powder, Cu-Zn composite coating was prepared on 1Cr13 substrate by low-pressure cold spray technique. The composite coating was annealed at different annealing temperatures, and then the mechanical properties of the coating were tested. Observing the micrographs and testing hardness of composite coatings before and after annealing heat treatment by X-ray diffractometer, field emission scanning electron microscope and microhardness tester. The results show that the copper-zinc composite coatings are dense and the coatings are tightly bonded to the substrate; When the copper-zinc composite coatings are annealed between 200 °C and 300 °C, the metal particles interfaces in the coatings are obvious, and intermetallic compounds are formed in the coatings, such as β(CuZn) and γ(Cu5Zn8). When the annealing temperature is 200 °C, the hardness of copper-zinc composite coating reaches the highest (157.8HV), and the bonding strength reaches the lowest (7.5MPa); When the copper-zinc composite coatings are annealed between 350 °C and 450 °C, the metal particles interfaces in the coatings are not obvious; When the annealing temperature is 450 °C, the hardness of copper-zinc composite coating reaches the lowest (102.4HV), and the bonding strength reaches the highest (13.9MPa).