A method (56) for fabricating an integral assembly (24) is disclosed. The method comprises providing (56) a first workpiece (26) having a first surface (46) and a second workpiece (28) having a second surface (50), performing a first bonding process between the first surface (46) of the first workpiece (26) and the second surface (50) of the second workpiece (28) to form a sub-assembly workpiece (48), and performing a second bonding process between a third surface (52) of the sub-assembly workpiece (48) and a fourth surface (54) of a third workpiece (30) to form the integral assembly (24). The material properties of the first workpiece (26) are different from material properties of the third workpiece (30).