Patent ID: 8333920

Claim:
A melt supply pipe for connecting a melting furnace and a plunger sleeve of a die casting machine, comprising: an inner ceramic pipe having terminal connecting portions that abut adjacent inner ceramic pipes; an outer steel pipe fitted, along its inside, around the inner pipe and configured to provide a clamp load to the terminal connecting portions to thereby reduce leakage of the melt supply through seams between abutting inner ceramic pipes; a Ni alloy layer formed over the inside of the outer steel pipe; TiC particles bonded to the surface of the Ni alloy layer, wherein the layer is formed over the inside of the outer steel pipe, along an inner circumferential surface that is not in contact with molten material in the inner ceramic pipe; and a pair of fibrous sheet members, composed of an inorganic material having the property of expanding by heating, sandwiched between the inner ceramic pipe and the outer steel pipe at both ends of the pipes, wherein the fibrous sheet members expand at a temperature of molten aluminum to prevent molten aluminum from leaking through gaps between the inner ceramic pipes to reach the outer steel pipe; wherein the TiC particles are bonded into the Ni alloy layer so that the TiC particles protrude inwardly, out of the Ni alloy layer on the inside surface of the outer steel pipe, toward the inner ceramic pipe, such that, as a function of the protruding TiC particles and positioning of the inner ceramic pipe within the outer steel pipe: (1) the TiC particles yield resistance to thermal stress even when the outer steel pipe expands or contracts, and (2) the TiC particles provide melt loss resistance from melt leaking through gaps between adjacent inner ceramic pipes to provide melting loss resistance of an enhanced nature over melt supply pipes that are absent TiC particulate material between inner and outer pipe elements; wherein the melt supply pipe yields improved durability and extended operational life at a temperature of molten aluminum as a function of arrangement of the TiC particles between the inner pipe and the outer pipe, which provides: (1) resistance to thermal stress stemming from expansion or contraction of the outer steel pipe, and (2) enhanced resistance of the outer steel pipe to melting loss caused by heat-related shock/stress given by contact with molten aluminum.