| 摘要 |
Specimens are mounted for study by enveloping them in a mixture of 10-30 parts by weight of powdered abrasive having a Knoop hardness of at least 900, and 80-120 parts of a curable resin, and curing the resin. A surface of the body thus obtained is then ground away to expose a portion of the specimen, e.g. a metallographic specimen for microscopic study. Suitable resins are the commercially available epoxy resins. In the example, powdered alumina less than 0.1 micron in size is mixed with a bis-phenol A-epichlorohydrin condensate diluted with butyl glycidyl ether. Diethylene triamine is added as curing agent, and the slurry poured into brass moulds containing the specimens for examination, and left to cure. After removal from the moulds and heating to complete the cure, the body of resin was ground to expose a surface of the specimen for polishing, etching and examination. The specimens may be of porous materials, e.g. metals, or of graphite. |
