Metallographic preparation of pressed and sintered powder metallurgy material (tungsten, columbium, lead and copper)

摘要

A metallographic preparation technique employs a grinding and polishing in four stages, and with multiple steps of each stage, to produce a flat, scratch-free representative sample of a pressed and sintered powder metallurgy material comprised of tungsten, lead, copper, and columbium.PPThe constituents, both hard and soft and in a predetermined weight percent range, are the hard constituents of tungsten and columbium and the soft constituents of lead and copper are finished to yield a sample suitable for microscopic and photomicrograph evaluations since the flatness of the sample and scratch-free surface permits viewing of the shape and size of the individual constituents. The standard prior art metallographic preparation procedure did not produce acceptable results because of the polishing procedure which rounded the refractory constituents and left them in relief. The soft constituents were not scratch free.