Method for manufacturing a metal protection device for the leading edge of a blade incorporating a de-icing system and protection device obtained by this method

A method for manufacturing a metal protection device for a leading edge of a composite material blade for a turbofan, the method comprising:

• a) shaping by die forging, a lower face sheet and an upper face sheet
• b) making a core having a shape identical to the shape of the leading edge of the blade,
• c) positioning the core between the lower surface and upper surface sheets,
• d) vacuumising and sealing the assembly by welding,
• e) assembling the assembly by hot isostatic pressing,
• f)_cutting the assembly and extracting the core,
• g) final machining to obtain a protection device with a predefined profile, wherein:
• on the one hand, operation a) includes machining, on an inner face of at least one of the lower surface and upper surface sheets, at least one groove adapted to receive a resistive element, and
• on the other hand, operation c) includes positioning the resistive element in the groove, the resistive element forming an electrothermal heater integrated into the metal protection device of the leading edge of the blade.