Gallery 3
Alan Stone

The director of Aston Metallurgical Services in Wheeling, Ill., ALAN STONE, makes his living by helping clients solve their metal-related problems. One such problem is "metal dusting," a situation in industrial settings in which the surfaces of furnace tubes, processing tubes, and other metal components turn to dust, sometimes with catastrophic results.

Images 1 and 2 in this gallery depict some microscale signs of metal dusting in a furnace tube. Image 3 shows a weld joining two pieces of copper tubing. The individual grains of the metal on each side of the weld are visible as irregular shapes with thin boundaries. Image 4 shows the mix of phases that form when ductile iron is hardened through a hot-flame process. Images 5 and 6 reveal the dendritic, or branched, grains of an ancient bronze arrowhead that Stone bought but couldn't help cutting up to examine metallographically. Dendritic grains form in some cast metals as they solidify from the melted state. The final three images, 7–9, are from metal that made its way from outer space to Earth in three different meteorites and finally into Stone's hands.

next gallery
Image 1 Image 2
Image 3
Image 4
Image 3 Image 4
Image 5 Image 6
Image 7
Image 8
Image 7 Image 8
Image 9


All images courtesy of Alan Stone