Convertible downhole devices

A convertible downhole device comprises at least one sacrificial material to provide two or more configurations so that two or more different operations or functions are performable by the downhole device, one in which the sacrificial material is fully intact and another in which the sacrificial material is at least partially removed or disappeared. The sacrificial material may be removable through any suitable method or device, such as by contacting with a fluid, by temperature, by pressure, or by combustion, ignition, or activation of a fusible or energetic material, or crushing or breaking up of a frangible material. Upon removal of the sacrificial material, the downhole device has at least one additional configuration so that at least a second operation can be performed by the downhole device.