| 摘要 |
FIELD: metallurgy. ^ SUBSTANCE: invention refers to manufacture of hollow items from aluminium alloys. Method involves fabrication of a hollow semi-finished product and heat treatment - ageing for the alloys strengthened with heat treatment, or annealing for the alloys non-strengthened with heat treatment. Heat treatment is performed in the device for heat fixing of external and/or internal surfaces of semi-finished product throughout its whole length or some part of length; at that, at heat fixing of external semi-finished product surface, as the device there used is sleeve made from steel with low thermal linear expansion coefficient with functional sleeve diametre calculated by the formula DSëêD[1+(a-s)tH-ast2ÇèH], where DS-functional sleeve diametre at normal temperature, D - outer diametre of semi-finished product at normal temperature, a - thermal linear expansion coefficient of aluminium alloy, s thermal linear expansion coefficient of steel from which sleeve is made, tH - heating temperature of semi-finished product and sleeve at final heat treatment (C). At thermal fixing of inner surface of semi-finished product, as the device there used is mandrel made from material with thermal linear expansion coefficient close to thermal linear expansion coefficient of semi-finished product metal with functional mandrel diametre calculated by the formula d ëñ dm ëñ (d + 0.5 öd) , where d - inner diametre of semi-finished product at normal temperature, dm - functional mandrel diametre at normal temperature, öd - allowance for inner semi-finished product diametre. ^ EFFECT: improving geometric relationship of hollow items from aluminium alloys of any geometric shape. ^ 2 dwg, 2 ex |
