A prechamber ignition device in an internal combustion engine is provided having a body piece formed of a first type of material and a tip piece formed of a second type of material. A distal end of the body piece has a cladding, which may be of the second type of material, for preventing corrosion of the first type of material from which the body piece is formed.

An apparatus is provided for a powerplant. This apparatus includes a pilot chamber structure formed as a monolithic body. The pilot chamber structure includes an exterior surface, an interior surface, a pilot chamber, a pilot aperture, a fuel aperture and an ignitor aperture. A material property of the monolithic body may change as the pilot chamber structure extends between the exterior surface and the interior surface. The interior surface forms an outer peripheral boundary of the pilot chamber. The pilot chamber is internal to the pilot chamber structure. The pilot aperture projects into the pilot chamber structure to the pilot chamber. The fuel aperture projects into the pilot chamber structure to the pilot chamber. The ignitor aperture projects into the pilot chamber structure to the pilot chamber.

An apparatus is provided for a powerplant. This apparatus includes a pilot chamber structure formed as a monolithic body. The pilot chamber structure includes an exterior surface, an interior surface, a pilot chamber, a pilot aperture, a fuel aperture and an ignitor aperture. A material property of the monolithic body may change as the pilot chamber structure extends between the exterior surface and the interior surface. The interior surface forms an outer peripheral boundary of the pilot chamber. The pilot chamber is internal to the pilot chamber structure. The pilot aperture projects into the pilot chamber structure to the pilot chamber. The fuel aperture projects into the pilot chamber structure to the pilot chamber. The ignitor aperture projects into the pilot chamber structure to the pilot chamber.