| Summary: | 碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 94 === Aluminum and copper have been widely used in many heat sink modules due to their high thermal conductivities. Conventionally, aluminum and copper were bonded by using thread or fixture fastened. However, for the consideration of bonding strengths and thermal conductivities of interface, in order to prepare a fine aluminum-copper heat dissipating apparatuses. Therefore, the aluminum-copper solid liquid interdiffusion bonding technology should be one of a worthy considering choice. In addition, for both lightening and heat dissipating considerations, the magnesium alloy has its development potential. Consequently, this study aimed to investigate aluminum-copper-magnesium solid liquid interdiffusion bonding technology, by heating above the eutectic temperature of aluminum-copper, magnesium-copper and aluminum-magnesium substrates, to produce solid liquid interdiffusion reaction. Make use of the characteristics of eutectic reaction for aluminum-copper at 485℃, aluminum-magnesium at 437℃ and magnesium-copper at 548℃, respectively. We introduced a rolling aluminum foil or copper foil, about 0.15mm in thickness, in the interface of joints. Applied above-mentioned binary alloy eutectic reaction to produce solid liquid interdiffusion and promote some local melting in the interface, fill in the clearance of bonding interface, can achieve the compact bonding and promote bonding strength within a short time.
Experimental results revealed that it is suitable for aluminum, copper foils to deal with solid liquid interdiffusion bonding, such as aluminum, copper, magnesium, without any intermediate layer or welding materials added. Considering the bonding strength, the optimized processing parameter for magnesium–aluminum foil–magnesium, magnesium–copper foil–magnesium and copper–aluminum foil–copper, is heating at 480℃, 510℃and 580℃and their maximum shear strengths are 74MPa, 19MPa and 26MPa, respectively. The proper holding time will be 60 minutes for above-mentioned tests. In addition, the intermetallic compound, for aluminum-magnesium, magnesium-copper and aluminum-copper, included ; , and ; ; AlCu, respectively. The interface reaction area of solid liquid interdiffusion bonding for aluminum-magnesium, magnesium-copper and aluminum-copper at constant heating temperature, the micro-hardness commonly increased as holding time increase.
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