Mold for manufacturing a turbomachine fan casing made of a composite material with differential expansion

A method for manufacturing a turbomachine fan casing made of a composite material with fibrous reinforcement densified by a matrix with a mould that includes

• an impregnation mandrel around which a fibrous preform is intended to be wound;
• a plurality of angular counter-mould sectors assembled around the external contour of the impregnation mandrel, which are intended to close the mould;
• wherein the impregnation mandrel comprises a main body and an annular barrel which is arranged around the main body and around which the fibrous preform is intended to be wound, the annular barrel and the plurality of angular counter-mould sectors defining a moulding cavity intended to receive the fibrous preform, the main body and the plurality of angular counter-mould sectors being made of a first material that has a first thermal expansion coefficient, the annular barrel being made of a second material that has a second thermal expansion coefficient, the second thermal expansion coefficient being greater than the first thermal expansion coefficient,
• wherein the main body comprises a flange located at each of the axial ends of the main body, each flange comprising a conical surface which is adapted to cooperate with a complementary conical surface located at each of the axial ends of the barrel, the annular barrel being adapted to slide along the conical surfaces of the flanges through a difference in thermal expansion between the main body and the annular barrel,
• the method comprising:
• winding a fibrous fan casing preform around the annular barrel of the impregnation mandrel;
• assembling the plurality of angular counter-mould sectors on the external contour of the impregnation mandrel around which the fibrous fan casing preform is wound;
• heating the mould in order to compress the fibrous fan casing preform between the annular barrel and the plurality of angular counter-mould sectors, and
• injecting a precursor material of the matrix into the fibrous preform, and
• polymerising the precursor material of the matrix.