Methods for site-specific enhancement of soft magnetic alloys
The present invention relates to methods of enhancing the surface properties of soft alloys by using a high energy beam. In particular embodiments, the methods can also allow for beam-based welding of such soft alloys to another metal component.
1. A method comprising:
providing a component comprising a soft magnetic alloy with a crystal structure having long-range atomic order; and
treating a surface portion of the component with a high energy beam, thereby melting and solidifying the surface portion to provide a treated surface portion, wherein the treated surface portion comprises a disordered surface layer having a grain size less than about 10 μm in size and a thickness of between 10 μm and 300 μm.
2. The method of claim 1 , wherein the soft magnetic alloy comprises iron and cobalt.
3. The method of claim 1 , wherein the high energy beam comprises a laser beam or an electron beam.
4. The method of claim 3 , wherein the laser beam comprises a wavelength of from about 1000 nm to about 1200 nm.
5. The method of claim 3 , wherein the laser beam comprises a continuous wave laser beam.
6. The method of claim 1 , wherein the high energy beam comprises a power of from about 200 W to about 500 W.
7. The method of claim 1 , wherein the high energy beam comprises a frequency oscillation of from about 250 Hz to 1 kHz.
8. The method of claim 1 , wherein the high energy beam is translated along a wobble path.
9. The method of claim 1 , wherein the high energy beam comprises a focused beam size of from about 20 μm to about 80 μm.
10. The method of claim 1 , wherein the solidifying comprises cooling at a rate of from about 500° C./see to about 5000° C./sec.
11. The method of claim 1 , wherein the treated surface portion comprises at least about 80% increase in tensile strain-to-failure, as compared to the surface portion prior to treatment.
12. The method of claim 1 , wherein the treated surface portion comprises at least about 30% increase in tensile strength, as compared to the surface portion prior to treatment.
13. The method of claim 1 , wherein the component comprises a solenoid, an actuator, a tape core, a magnetic core, a rotor, a stator, a magnetic bearing, a motor, or a generator.
14. The method of claim 1 , wherein the crystal structure having long-range atomic order comprises an ordered B2 or DO3 crystal structure.