ALUMINUM ALLOY EXTRUSION MATERIAL HAVING EXCELLENT SURFACE PROPERTY, METHOD FOR PRODUCING THE SAME, PERFORATED TUBE FOR HEAT EXCHANGER, AND METHOD FOR PRODUCING HEAT EXCHANGER WITH THE PERFORATED TUBE INCORPORATED

摘要

PROBLEM TO BE SOLVED: To provide an aluminum alloy extrusion material having excellent surface properties with which a thinned perforated tube can be subjected to extrusion at a high critical extrusion rate, and which causes no problem of sticking depositions to the surface of the extruded tube and is suitably usable as the component of an automobile heat exchanger made of an aluminum alloy in particular. SOLUTION: The aluminum alloy extrusion material having excellent surface properties has a composition comprising 0.8 to 1.6% Mn and 0.4 to 0.8% Si, and in which the ratio between the Mn content and the Si content, (Mn%/Si%) is controlled to 0.7 to 2.4, and the balance Al with inevitable impurities, and in which the number of intermetallic compounds with a particle diameter (diameter of the equivalent circle) of 0.1 to 0.9μm dispersed into a matrix is≥2×105pieces/mm2. COPYRIGHT: (C)2007,JPO&INPIT