Corrosion-resistant aluminum alloy for heat exchanger
An extrudable aluminum alloy for a micro channel and round tube heat exchanger application including silicon in an amount that ranges between 0.15 and 0.30 wt %, iron in an amount that is less than or equal to 0.15 wt %, manganese in amount that ranges between 0.50 and 0.90 wt %, zinc in amount of no greater than 0.03 wt %, copper in amount of no greater than 0.03 wt %, and nickel in an amount of no greater than 0.01 wt %.
1. An extrudable aluminum alloy for a micro channel and round tube heat exchanger application consisting essentially of:
silicon in an amount that ranges between 0.21 and 0.30 wt %;
iron in an amount that is less than or equal to 0.15 wt %;
manganese in an amount that ranges between 0.50 and 0.90 wt %;
zinc in an amount of no greater than 0.03 wt %;
copper in an amount of no greater than 0.03 wt %;
nickel in an amount of no greater than 0.01 wt %; and
a balance of aluminum,
wherein the aluminum alloy has a dispersoid number density in the range of 16 to 23 per 100 square microns.
2. The extrudable aluminum alloy of claim 1 , wherein the alloy is casted as a billet and homogenized, wherein homogenization includes soaking the billet at a temperature that ranges between 575° C. and 625° C. and cooling the billet at a controlled rate ranging between 150° C./hour and 225° C./hour.
3. The extrudable aluminum alloy of claim 2 , wherein the billet has a conductivity (% IACS) between 37 and 46 after homogenization.
4. The extrudable aluminum alloy of claim 1 , wherein the alloy exhibits an electro-potential that ranges between −745 and −775 mV.
5. The extrudable aluminum alloy of claim 1 , wherein the manganese content is in the range of 0.50 and 0.70 wt %.
6. The extrudable aluminum alloy of claim 1 , wherein the manganese content is in the range of 0.70 and 0.90 wt %.
7. A method of manufacturing an aluminum alloy billet, comprising:
forming an aluminum alloy that consists essentially of silicon in an amount that ranges between 0.21 and 0.30 wt %; iron in an amount that is less than or equal to 0.15 wt %; manganese in an amount that ranges between 0.50 and 0.90 wt %; zinc in an amount of no greater than 0.03 wt %; copper in an amount of no greater than 0.03 wt %; nickel in an amount of no greater than 0.01 wt %; and a balance of aluminum;
casting the aluminum alloy into a billet;
homogenizing the billet by heating the billet to a temperature in the range of 550° C. to 625° C.;
soaking the billet at the temperature; and
cooling the billet to room temperature,
wherein the billet has a dispersoid number density in the range of 16 to 23 per 100 square microns.
8. The method of claim 7 , wherein the step of cooling includes cooling the billet at a controlled rate of 150° to 225° C./hour.
9. The method of claim 7 , further comprising extruding the billet into a tube and brazing the extruded tube, wherein the extruded tube after brazing has a small grain structure.
10. The method of claim 7 , wherein the billet has a conductivity (% IACS) between 37 and 46.
11. The method of claim 7 , further comprising extruding and brazing the alloy.
12. The method claim 7 , wherein the alloy exhibits an electro-potential that ranges between −745 and −775 mV.
13. The method of claim 7 , wherein the manganese content is in the range of 0.50 and 0.70 wt %.
14. The method of claim 7 , wherein the manganese content is in the range of 0.70 and 0.90 wt %.
15. The extrudable aluminum alloy according to claim 1 , wherein the amount of nickel is in the range of 0.002 to 0.01 wt %.
16. The method of claim 7 , wherein the alloy includes an amount of nickel that is in the range of 0.002 to 0.01 wt %.