Aluminum alloy clad material

An aluminum alloy clad material which is composed of:

• (a) a core material made of an aluminum alloy consisting of, in weight percentages, 0.3 to 1.5% manganese, 0.05 to 0.35% copper, 0.05 to 0.50% magnesium, 0.06 to 0.35% titanium, less than 0.1% silicon and up to 0.3% iron, with the proviso that the copper content is related to the magnesium content in accordance with the following equation:
• Cu(%)-0.2.ltoreq.Mg(%).ltoreq.Cu(%)+0.2,
• the balance being aluminum and incidental impurities, wherein the number of Mn compound particles having a diameter (equivalent diameter) of 0.1 .mu.m or less is up to 35% of the total number of all Mn compound particles and the Ti content periodically varies along the thickness of said core material with a period width of Ti content variation of from 2 to 50 .mu.m, and
• (b) a cladding material made of an Si-containing aluminum alloy brazing filler material clad onto one or both sides of said core material.

A heat exchanger comprising:

• a fluid inlet tank into which a heat exchange fluid flows,
• at least one tube connected at a fluid entrance end thereof to said fluid inlet tank and allowing said heat exchange fluid to pass therethrough,
• a fluid outlet tank connected to a fluid exit end of said tube and thereby allowing said heat exchange fluid flowing from said tube to enter said fluid outlet tank, and
• fins brazed onto an external surface of said tube, wherein said tube is made of an aluminum alloy clad material which is composed of:
• (a) a core material made of an aluminum alloy consisting of, in weight percentage, 0.3 to 1.5% manganese, 0.05 to 0.35% copper, 0.05 to 0.50% magnesium, 0.06 to 0.35% titanium, the Ti content periodically varying along the thickness of the core material with a period width of Ti content variation of from 2 .mu.m to 50 .mu.m, less than 0.1% silicon and up to 0.3% iron, with the proviso that the copper content is related to the magnesium content in accordance with the following equation:
• Cu(%)-0.2.ltoreq.Mg(%).ltoreq.Cu(%)+0.2,
• the balance being aluminum and incidental impurities and
• (b) a cladding material made of an Si-containing aluminum alloy brazing filler material clad onto one or both sides of said core material.

A heat exchanger comprising:

• a fluid inlet tank into which a heat exchange fluid flows, at least one tube connected at a fluid entrance end thereof to said fluid inlet tank and allowing said heat exchange fluid to pass therethrough,
• a fluid outlet tank connected to a fluid exit end of said tube and thereby allowing said heat exchange fluid flowing from said tube to enter said fluid outlet tank, and
• fins brazed onto an external surface of said tube, wherein said tube is made of an aluminum alloy clad material which is composed of:
• (a) a core material made of an aluminum alloy consisting of, in weight percentages, 0.3 to 1.5% manganese, 0.05 to 0.35% copper, 0.05 to 0.50% magnesium, 0.06 to 0.35% titanium, less than 0.1% silicon and up to 0.3% iron, with the proviso that the copper content is related to the magnesium content in accordance with the following equation:
• Cu(%)-0.2.ltoreq.Mg(%).ltoreq.Cu(%)+0.2,
• the balance being aluminum and incidental impurities, wherein the number of Mn compound particles having a diameter (equivalent diameter) of 0.1 .mu.m or less is up to 35% of the total number of all Mn compound particles and the Ti content periodically varies along the thickness of said core material with a period width of Ti content variation of from 2 to 50 .mu.m, and
• (b) a cladding material made of an Si-containing aluminum alloy brazing filler material clad onto one or both sides of said core material.