Embodiments disclosed are systems and methods for fabricating microchannels in metal. In an embodiments, a method includes providing a first metallic plate having a first surface with an elongated slot recessed therein, providing a second metallic plate having a second surface, interfacing the first surface of the first metallic plate with the second surface of the second metallic plate with the second surface covering the elongated slot to form a microchannel between the first metallic plate and the second metallic plate, thermal bonding the first metallic plate to the second metallic plate to form a metallic body having the microchannel extending therethrough, and infiltrating the metallic body with an infiltrant.

Provided is a valve seat insert for an internal combustion engine, which has both an excellent heat dissipation property and excellent wear resistance. The valve seat insert for an internal combustion engine is used while being press-fitted into an aluminum alloy cylinder head, is made of an iron-based sintered alloy, is formed by integrating two layers of a functional member side layer and a supporting member side layer, and has a plating film on at least an outer peripheral side. The plating film is preferably a copper plating film. The plating film is a plating film having a thickness of 1 to 100 μm and a hardness of 50 to 300 HV, and the hardness of the plating film is adjusted so as to satisfy a range of 1.05 to 4.5 times hardness of the cylinder head in Vickers hardness HV. Pores contained in the valve seat insert are preferably sealed with a curable resin before plating treatment. Consequently, a valve seat insert for an internal combustion engine which does not go through complicated processes, is not accompanied by a significant decrease in wear resistance compared with the prior art, and has an excellent heat dissipation property is provided. If a roughened surface region is further formed at at least one portion on the outer peripheral surface of the valve seat insert in addition to the plating film, a falling out resistance property is improved. The same effect can be obtained even if the valve seat insert is a single layer of only the functional member side layer.

Provided is a valve seat insert for an internal combustion engine, which has both an excellent heat dissipation property and excellent wear resistance. The valve seat insert for an internal combustion engine is used while being press-fitted into an aluminum alloy cylinder head, is made of an iron-based sintered alloy, is formed by integrating two layers of a functional member side layer and a supporting member side layer, and has a plating film on at least an outer peripheral side. The plating film is preferably a copper plating film. The plating film is a plating film having a thickness of 1 to 100 μm and a hardness of 50 to 300 HV, and the hardness of the plating film is adjusted so as to satisfy a range of 1.05 to 4.5 times hardness of the cylinder head in Vickers hardness HV. Pores contained in the valve seat insert are preferably sealed with a curable resin before plating treatment. Consequently, a valve seat insert for an internal combustion engine which does not go through complicated processes, is not accompanied by a significant decrease in wear resistance compared with the prior art, and has an excellent heat dissipation property is provided. If a roughened surface region is further formed at at least one portion on the outer peripheral surface of the valve seat insert in addition to the plating film, a falling out resistance property is improved. The same effect can be obtained even if the valve seat insert is a single layer of only the functional member side layer.

A reactive matrix infiltration process is described herein, which includes contacting a surface of a preform comprising reinforcement material particles with a molten infiltrant comprising a matrix material, the matrix material comprising an Al—Ce alloy, whereby the infiltrant at least partially fills spaces between the reinforcement material particles by capillary action and reacts with the reinforcement material particles to form a composite material form, the composite material comprising the matrix material, at least one intermetallic phase, and, optionally, reinforcement material particles. A composite material form also is described, which includes a plurality of reinforcement material particles comprising a metal alloy or a ceramic, a matrix material at least partially filling spaces between the reinforcement material particles; and at least one intermetallic phase surrounding at least some of the reinforcement material particles. The reinforcement material particles and intermetallic phase together may form a gradient core-shell structure.

A reactive matrix infiltration process is described herein, which includes contacting a surface of a preform comprising reinforcement material particles with a molten infiltrant comprising a matrix material, the matrix material comprising an Al—Ce alloy, whereby the infiltrant at least partially fills spaces between the reinforcement material particles by capillary action and reacts with the reinforcement material particles to form a composite material form, the composite material comprising the matrix material, at least one intermetallic phase, and, optionally, reinforcement material particles. A composite material form also is described, which includes a plurality of reinforcement material particles comprising a metal alloy or a ceramic, a matrix material at least partially filling spaces between the reinforcement material particles; and at least one intermetallic phase surrounding at least some of the reinforcement material particles. The reinforcement material particles and intermetallic phase together may form a gradient core-shell structure.

An embodiment of a PCD insert comprises an embodiment of a PCD element joined to a cemented carbide substrate at an interface. The PCD element has internal diamond surfaces defining interstices between them. The PCD element comprises a masked or passivated region and an unmasked or unpassivated region, the unmasked or unpassivated region defining a boundary with the substrate, the boundary being the interface. At least some of the internal diamond surfaces of the masked or passivated region contact a mask or passivation medium, and some or all of the interstices of the masked or passivated region and of the unmasked or unpassivated region are at least partially filled with an infiltrant material.

An embodiment of a PCD insert comprises an embodiment of a PCD element joined to a cemented carbide substrate at an interface. The PCD element has internal diamond surfaces defining interstices between them. The PCD element comprises a masked or passivated region and an unmasked or unpassivated region, the unmasked or unpassivated region defining a boundary with the substrate, the boundary being the interface. At least some of the internal diamond surfaces of the masked or passivated region contact a mask or passivation medium, and some or all of the interstices of the masked or passivated region and of the unmasked or unpassivated region are at least partially filled with an infiltrant material.

A method for producing an additively manufactured, graded composite transition joint (AM-GCTJ) includes preparing a grating or lattice pattern from a first alloy A; the grating or lattice pattern includes pores in the grating or lattice patterns. The grating pattern is built from a first end to a second end being denser on the first end than on second end, and gradually reduces density by increasing the pore size and/or reducing density of the grating or lattice pattern; adding a second alloy B powder to the second end of grating or lattice pattern. The second alloy B powder is filled towards the first end. A composite is formed of first alloy A and second alloy B powder in the AM-GCTJ. The composite is subjected to hot isotropic pressing (HIP) to densify the composite. The second alloy B is graduated from the first end to the second end O of AM-GCTJ.

A method for producing an additively manufactured, graded composite transition joint (AM-GCTJ) includes preparing a grating or lattice pattern from a first alloy A; the grating or lattice pattern includes pores in the grating or lattice patterns. The grating pattern is built from a first end to a second end being denser on the first end than on second end, and gradually reduces density by increasing the pore size and/or reducing density of the grating or lattice pattern; adding a second alloy B powder to the second end of grating or lattice pattern. The second alloy B powder is filled towards the first end. A composite is formed of first alloy A and second alloy B powder in the AM-GCTJ. The composite is subjected to hot isotropic pressing (HIP) to densify the composite. The second alloy B is graduated from the first end to the second end O of AM-GCTJ.

The present invention provides an aqueous polymer dispersion comprising at least one polymer having a carboxyl group and optionally an additional functional group selected from hydroxy, isocyanate, fluoro, phosphate, hydrazide, acetoacetate group and combination thereof, in which the polymer has a glass transition temperature of larger than −40° C. and less than 35° C., and the aqueous polymer dispersion has a solid content of larger than 50% by weight.