Gaseous emissions treatment components and methods for manufacturing thereof

A method of making a gaseous emissions treatment component, comprising extruding green ceramic mix through a die to form an extrusion having a honeycomb substrate having a plurality of elongate cells extending along the extrusion, the cells bounded by walls dividing adjacent cells from one another, cutting off a length of the extrusion, placing molten metal for use in induction heating of the component in at least a part of at least some of the cells in said length, and solidifying the molten metal by cooling, wherein said cooling acts to cool and solidify the molten metal to cause first shrinkage of the metal and acts to cool the substrate to cause second shrinkage of the substrate less than the first shrinkage, whereby at solidification of the molten metal, a space is established at at least some of an interface between the solidified metal and adjacent walls of said at least some of the cells.