Aluminum alloy extruded product exhibiting excellent surface properties, method of manufacturing the same, heat exchanger multi-port tube, and method of manufacturing heat exchanger including the multi-port tube
First Claim
1. A method of manufacturing an aluminum alloy extruded product exhibiting excellent surface properties and with the number of intermettalic compounds having a circle equivalent diameter of 0.1 to 0.9 μ
- m dispersed in the alloy matrix being at least 2×
105 per square millimeter, the method comprising;
melting and casting an aluminum alloy having a composition consisting of, in mass %, 0.8-1.6% of Mn and 0.4-0.8% Si, at a Mn/Si content of 0.7-2.4 and, optionally, 0.2% or less of Mg, 0.30% or less of Ti, 0.05% or less of Cu and 0.7% or less of Fe, with the balance being Al, to obtain an ingot;
subjecting the ingot to homogenization which includes a first-stage heat treatment in which the ingot is maintained at 550 to 650°
C. for two hours or more and a second-stage heat treatment in which the ingot is cooled to 400 to 500°
C. at an average temperature decrease rate of 20 to 60°
C./h and maintained at that temperature for three hours or more;
heating the ingot at 480 to 560°
C.; and
extruding the ingot.
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Abstract
An aluminum alloy extruded product exhibiting excellent surface properties, contains 0.8 to 1.6% of Mn and 0.4 to 0.8% of Si at a ratio of Mn content to Si content (Mn %/Si %) of 0.7 to 2.4, with the balance being Al and inevitable impurities, the number of intermetallic compounds with a diameter (circle equivalent diameter) of 0.1 to 0.9 μm dispersed in a matrix being 2×105 or more per square millimeter. The aluminum alloy extruded product allows extrusion of a thin multi-port tube at a high limiting extrusion rate, prevents deposits from adhering to the surface of the extruded tube, and may be suitably used as a constituent member for an aluminum alloy automotive heat exchanger.
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Citations
4 Claims
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1. A method of manufacturing an aluminum alloy extruded product exhibiting excellent surface properties and with the number of intermettalic compounds having a circle equivalent diameter of 0.1 to 0.9 μ
- m dispersed in the alloy matrix being at least 2×
105 per square millimeter, the method comprising;
melting and casting an aluminum alloy having a composition consisting of, in mass %, 0.8-1.6% of Mn and 0.4-0.8% Si, at a Mn/Si content of 0.7-2.4 and, optionally, 0.2% or less of Mg, 0.30% or less of Ti, 0.05% or less of Cu and 0.7% or less of Fe, with the balance being Al, to obtain an ingot;
subjecting the ingot to homogenization which includes a first-stage heat treatment in which the ingot is maintained at 550 to 650°
C. for two hours or more and a second-stage heat treatment in which the ingot is cooled to 400 to 500°
C. at an average temperature decrease rate of 20 to 60°
C./h and maintained at that temperature for three hours or more;
heating the ingot at 480 to 560°
C.; and
extruding the ingot. - View Dependent Claims (3)
- m dispersed in the alloy matrix being at least 2×
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2. A method of manufacturing an aluminum alloy extruded product exhibiting excellent surface properties and with the number of intermetallic compounds having a circle equivalent diameter of 0.1 to 0.9 μ
- m dispersed in the alloy matrix being at least 2×
105 per square millimeter, the method comprising;
melting and casting an aluminum alloy having a composition consisting of, in mass %, 0.8-1.6% of Mn and 0.4-0.8% Si, at a Mn/Si content of 0.7-2.4 and, optionally, 0.2% or less of Mg, 0.30% or less of Ti, 0.05% or less of Cu and 0.7% or less of Fe, with the balance being Al, to obtain an ingot;
subjecting the ingot to homogenization which includes a first-stage heat treatment in which the ingot is maintained at 550 to 650°
C. for two hours or more and a second-stage heat treatment in which the ingot is cooled to room temperature, heated to 400 to 500°
C. at an average temperature increase rate of 20 to 60°
C./h, and maintained at that temperature for three hours or more;
heating the ingot at 480 to 560°
C.; and
extruding the ingot. - View Dependent Claims (4)
- m dispersed in the alloy matrix being at least 2×
Specification