relative displacement between the layers is prevented or at least substantially resisted during expansion an outer layer 72 or 74 may be yielded to an extent greater than that of an inner layer 74 or 76 so that residual tensile hoop stress remains in an outer layer and residual compressive hoop stress remains in an inner layer after the expansion process is completed in addition the layers 72 74 76 may have different material properties different thicknesses etc as described above for the layers 50 52 54 56 of the structure 16 to enhance sealing between the expanded liner hanger 70 and the tubular member 42 46 in which it is expanded the liner hanger preferably includes a sealing material 78 the sealing material 78 may be configured as a part of the outer layer 72 as depicted in fig1 or it may be separately attached externally on the outer layer 72 the sealing material 78 may be an elastomer such as a nitrile or fluorocarbon material it may be a nonelastomer such as ptfe or peek material or it may be a metal such as lead etc thus it should be understood that any type of sealing material 78 may be used in the liner hanger 70 in keeping with the principles of the invention the sealing material 78 could be incorporated into the outer layer 72 for example by providing the.