热交换器用铝合金复合管材的制备新技术

A new technique manufacture aluminium alloy cladding pipe for heat exchanger

采用自行设计制造的包覆铸造装置成功制备出尺寸为Φ140 mm/Φ110 mm的4045/3003铝合金包覆铸锭,通过反向热挤压将包覆铸锭制备成铝合金复合管材.通过OM、SEM、拉伸实验、剪切实验对界面组织和性能进行了分析和测定.结果表明,利用该装置制备的铝合金包覆铸锭表面质量良好,界面清晰,无气孔、夹杂,界面处元素发生互扩散,并形成约20μm的过渡层,平均抗拉强度为103.3 MPa,抗剪切强度为80.2 MPa,两种合金实现冶金结合.反向热挤压后得到的复合管材,界面处保持了铸态时的层状结构特点.

Through the self - designed and manufactured cladding casting equipment, 4045/3003 composite billet of Ф140 mm/Ф110 mm was prepared. By using opposite direction extrudation of the cladding billet, the cladding pipe was produced. Texture and property of the interface were examined by OM, SEM, tensile and shear test. The results showed that the prepared cladding billet has a clean and clear interface with no porosities and inclusions. Si and Mn elements diffuse across the interface and form a diffusion layer about 20 μm. Tensile and shear strengs on the interface reach 103. 3 MPa and 80. 2 MPa, respectively, indicating that the two kinds of alloys have a metallurgical bonding. The laminated characteristic does not change during the extrudation process.