Powders of non-lamellar structure

74.06 - Copper powders and flakes. 7406.10 - Powders of non-lamellar structure 7406.20 - Powders of lamellar structure; flakes This heading covers copper owders as defined in Note 8 (b) to Section XV and copper flakes, other than cement copper brecipitated copper) which is a black powder of heading 74.01. Subject to the provisions of Note 7 to Section XV,it also covers cop er powders mixed with other base metal powders (e.g., " bronze powder " consisting of a simp e mixture of copper and tin powders). P Copper powders are mainly produced by electrodeposition or by atomisation (i.e., by injecting a thin stream of molten metal into a high-velocity cross-jet of water, steam, air or other gases). In addition to the above two main rocesses, co er powders may also be roduced on a smaller scale by gaseous reduction of inely divide oxides, preci itation #om solutions or by comminution of solids. Powders of lamellar structure and fla es are normally roduced by nding foil. The lamellar shape can be seen by the naked eye or through a magni&ng glass in t e case of flakes, but a microscope is needed for true powders. g T' %? t The method of manufacture determines such characteristics as the article size and sha e (which may be more or less irregular, globular, spherical or lamellar). owders with a lamel ar structure are often olished and may retain traces of greasy or waxy substances (e.g., stearic acid or paraffin waxy used in the course of their prepmation. I! P The powders are used for compacting and sintering into bearings, bushings and many other technical components. They are also used as chemical or metallurgical reagents, for soldering and brazing, in the manufacture of special cements, for coatmg non-metallic surfaces as a basis for electroplatin , etc. The flakes are mainly used as a metallic pigment in the manufacture of inks and paints. t h e flakes are used directly as metallic colouring matter by blowing them, e.g., on to a varnished surface to which they adhere. The heading does not cover : (a) Certain owders or flake-powders used in the preparation of paints and sometimes hown as "bronzes " n" g~l& " but which are in fist chemical compomds, such as certain antimony salts, tin disulphides, etc. (Chapter 28, or Chapter 32 if in the form of prepared paints). (b) Powders or flakes, prepared as colours, paints or the like (e-g.,made up with other colouring matter or put up as suspensionsydispersions or pastes, with a binder or solvent) (Chapter 32). (c) Copper shot of heading 74.03. (d) Spangles cut from copper foil (heading 83.08).