REINFORCED METALS

Evening Post, Volume CIII, Issue 144, 21 June 1922, Page 8

REINFORCED METALS

The idea of reinforaing metals in order effectively to combine the different properties of two or more metals is by no means new. The old: Sheffield ■ electroplate and < armour plate provide.- two well-known examples.. Usually.the meiala -to.be oombmed,.;are, suitably cleaned and sweated or rolled together at an elevated temperature. , There ' are, however, other | methods of achieving a similar end By !-the -.process, of electro-deposition reinforced or. -sandwiched metals; or what may reasonably be called two or three ply metals, may be readily produced. Copper-plated mild steel provides one example. In its manufacture the steel sheets., are first perforated. They ara subsequently cleaned and prepared for electro deposition. Copper deposit?, on* both. sides of the sheet are connected by deposited copper,in the perforations, and a very satisfactory adherent deposit is thus obtained. As circumstances may dictate, the copper deposits may be. of the same or different thioknesses. The on« side may be only sufficiently thick to provide, as it were, the element of countersinking to small deposits of copper within the perforations. These, being small, are soon 'filled up by the electro-deposit-ed .copper, though the , deposit... shows slight depressions opposite to each perforation., ' ', ' ,:• In the ; case- of, copper,' reinforced by steel, the compound metal may nqw undergo r degree of cold rolling, both the coppor and steel being reduced in thickness. The copper-filled circular- perforation? become slightly deformed to oval as an evidence- of. the rolling of tho perforated steel. Such a compound metal would seem to have many openings where,. it is desirable to add to the strength of the copper without. undue increase of thickness, and large'tanks now made, from, icopper sheet might apparently- be more successfully turned out from the newproduct. Copper provides but one- example of&n external covering. Lead , may be similarly^ applied with equal success, tbi . lead being deposited from one of the more modern lead , electrolyte. Special care must be taken with regard to1 the preliminary, cleaning o£ the steel in order to guarantee perfect adhesion' -during gentle rolling, as tho comparatively soft metal deposited in tho perforations has a marked degree of flow under pressure.