Composite fan blade

1. A blade fabrication method, comprising:

additively manufacturing a core;

securing the core to a mandrel, the securing comprising inserting an alignment pin into the core and the mandrel;

electroforming a leading edge sheath directly onto the core and the mandrel; and

removing the mandrel from the core and the leading edge sheath.

2. The blade fabrication method according to claim 1 , wherein the additively manufacturing comprises direct metal laser sintering (DMLS).

3. The blade fabrication method according to claim 1 , wherein the additively manufacturing comprises additively manufacturing the core to be latticed in interior portions thereof and perforated at outer portions thereof.

4. The blade fabrication method according to claim 1 , wherein the electroforming comprises electroforming the leading edge sheath to comprise:

an elongate leading edge portion that extends forwardly from a leading edge of the core; and

sidewall portions that extend rearwardly from a trailing edge of the elongate leading edge portion along the core and a forward portion of the mandrel.

5. The blade fabrication method according to claim 4 , further comprising locally thickening the sidewall portions of the leading edge sheath around a trailing edge of the core to form, for each of the sidewall portions, a thickened section that extends partially around and abuts with a proximal section of the trailing edge of the core and that facilitates retention of the core by the leading edge sheath.

6. The blade fabrication method according to claim 1 , wherein the removing comprises inserting one or more wedges between the leading edge sheath and the mandrel.

7. The blade fabrication method according to claim 1 , further comprising bonding a blade body to the core and the leading edge sheath, wherein the bonding comprises adhering the blade body to the core and the leading edge sheath.

8. A method of fabricating a blade for use in a flowpath, comprising:

additively manufacturing a core having a length sufficient to span a fraction of the flowpath;

securing the core to a mandrel having a length sufficient to span the fraction of the flowpath, the securing comprising inserting an alignment pin into the core and the mandrel;

electroforming a leading edge sheath directly onto the core and the mandrel;

separating the mandrel from the leading edge sheath along an entirety of the length of the mandrel; and

removing the mandrel from the core and the leading edge sheath.

9. The method according to claim 8 , wherein the additively manufacturing comprises direct metal laser sintering (DMLS).

10. The method according to claim 8 , wherein the additively manufacturing comprises additively manufacturing the core to be latticed in interior portions thereof and perforated at outer portions thereof.

11. The method according to claim 8 , wherein the electroforming comprises electroforming the leading edge sheath to comprise:

an elongate leading edge portion that extends forwardly from a leading edge of the core; and

sidewall portions that extend rearwardly from a trailing edge of the elongate leading edge portion along the core and a forward portion of the mandrel.

12. The method according to claim 11 , further comprising locally thickening the sidewalls portions of the leading edge sheath around a trailing edge of the core to form, for each of the sidewall portions, a thickened section that extends partially around and abuts with a proximal section of the trailing edge of the core and that facilitates retention of the core by the leading edge sheath.

13. The method according to claim 8 , wherein the removing comprises inserting one or more wedges between the leading edge sheath and the mandrel.

14. The method according to claim 8 , further comprising bonding a blade body to the core and the leading edge sheath, wherein the bonding comprises adhering the blade body to the core and the leading edge sheath.

15. A method of assembling a leading edge sheath assembly for a blade having a blade body, the method comprising:

additively manufacturing a core perforated at outer portions thereof and latticed in interior portions thereof, the core comprising leading and trailing edges and first and second sidewalls extending between the leading and training edges;

securing the core to a mandrel;

electroforming a leading edge sheath directly onto the core and the mandrel, the leading edge sheath comprising:

an elongate leading edge portion extending forwardly from the leading edge of the core; and

sidewall portions extending rearwardly from the elongate leading edge portion along and beyond the first and second sidewalls of the core, each of the sidewall portions comprising a thickened section extending partially around and abuts with a proximal section of the trailing edge of the core;

separating the mandrel from the leading edge sheath; and

removing the mandrel from the core.

16. The method according to claim 15 , wherein the separating of the mandrel from the leading edge sheath comprises inserting one or more wedges between the leading edge sheath and the mandrel.

17. The method according to claim 15 , further comprising bonding a blade body to the core and the leading edge sheath, wherein the bonding comprises adhering the blade body to the core and the leading edge sheath.