Method of fabricating a torque converter with an etched clutch surface and a torque converter with an etched clutch surface

1. A method of fabricating a torque converter, comprising:

forming a turbine shell including a first annular portion, the first annular portion:

including a first surface having a first roughness; and,

forming a radially outermost portion of the turbine shell;

fixedly connecting a first plurality of blades to the turbine shell;

forming an impeller shell including a second annular portion having a second surface with a second roughness;

fixedly connecting a second plurality of blades to the impeller shell;

bombarding the first or second surface with particles of solidified carbon dioxide or with particles of NaHCO 3 ;

applying an adhesive to the bombarded first or second surface; and,

bonding friction material to the bombarded first or second surface with the adhesive.

2. The method of claim 1 , further comprising:

when the first surface is bombarded with NaHCO 3 , washing the turbine shell and the first plurality of blades to remove particles of NaHCO 3 remaining in or on the turbine shell or the first plurality of blades; or,

when the second surface is bombarded with NaHCO 3 , washing the impeller shell and the second plurality of blades to remove particles of NaHCO 3 remaining in or on the impeller shell or the second plurality of blades.

3. The method of claim 1 , wherein:

fixedly connecting the first plurality of blades to the turbine shell includes:

applying brazing material to the turbine shell or the first plurality of blades; and,

heating the turbine shell, brazing material, and first plurality of blades.

4. The method of claim 3 , further comprising, prior to removing the at least a portion of the first or second surface:

machining the first surface to attain the first roughness.

5. The method of claim 1 , wherein:

fixedly connecting the second plurality of blades to the impeller shell includes:

applying brazing material to the impeller shell or the second plurality of blades; and,

heating the impeller shell, brazing material, and second plurality of blades.

6. The method of claim 5 , further comprising, prior to removing the at least a portion of the first or second surface:

machining the second surface to attain the second roughness.

7. The method of claim 1 , further comprising:

assembling the turbine and the impeller with a stator including a third plurality of blades.

8. The method of claim 7 , further comprising:

fixedly connecting the impeller shell to a cover for the torque converter.