PLANE BRAKES OF POWDER

Bay of Plenty Beacon, Volume 5, Issue 60, 3 June 1942, Page 6

PLANE BRAKES OF POWDER

KILL WITHIN SECONDS BOMBER'S 6,000,000 FOOT-POUNDS OF ENERGY Brakes of bombing" anil lighting aircraft, which have to lie tougher than any others, are being made in Britain l'rom metal powders. This process, a comparatively recent development in metallurgy originally discovered by an Englishman enables the bronze friction plates lor the disc-like brakes, Avith Avhich many planes are now provided, to stand up to the tremendous friction involved in bringing to a standstill a mass of some 40.1)001 bs travelling at a velocity of 100 miles an hour, when in a moment cr so the brakes assembly may well reach a temperature of about 900 deg. Fahr. Motorists know how easy it is to burn out their brake linings* under conditions much less strenuous than these: while on other forms of surfaces transport, such as trains, there are many Avhcels to each of which brakes can be applied simultaneously. But the aeroplane, as at present designed, has only two wheels to Avhich l brake assemblies can be attdied. In the case of a bomber, the brakes on each wheel have to kill about 0,000,000 foot-pounds of energy in a few .seconds. Odd though it may seem that metal powders can provide materials capaible of standing up to such conditions, they do so. The bronze is produced by mixing proportions pf the component metals l in line pow-I der form, Avhich are then pressed in powerful hydraulic presses into the desired shape and size. The slabs thus produced arc now passed into furnaces' Avhere the heat is so controlled that the mass is sintered, I hat is, the low. melting point component melts and alloys Avith the high melting point component. The heat treatment is such that as perfect an alloy is formed as if the part had been produced from cast iron; moreover, the use of powders giA-es infinitely greater control over the properties of the resulting metal l part and allowed it to be bonded direct on to steel backing. This reinforces the strength of the part and the whole assembly is capable of standing up to the tremendous strains involved in bringing a heavy aeroplane quickly and safety to rest.