| 摘要 |
The invention relates to an innovative aluminium casting method for producing engine and compressor blocks, integrating controlled and directed heat extraction and the application of a rotary mechanical action during the controlled solidification of an aluminium alloy. This technique makes it possible to produce metallic parts with multiple inner layers, each with physical and mechanical properties that can be controlled during the precipitation of hard crystalline (intermetallic) phases associated with the ductile aluminium phases. The multiple layers generated inside the cast products are produced from a single chemical composition which is initially designed or to which chemical alloying elements are added after the beginning of solidification. For this purpose, the composition of the aluminium alloy bath is controlled, which bath must contain the following concentration of transition elements, in percentages by weight: 3.0%-10% silicon; 0.5%-2.5% iron; 0.1%-3.0% manganese; 0.1%-3.0% copper; 0.01%-1.0% chromium, the remainder being aluminium and any other residual elements such as nickel, magnesium and strontium. The sleeves are obtained by controlled deposition of crystalline metal phases having high hardness (above 1100 HV) intercalated with ductile (soft) phases, in radially predefined layers, forming a sandwich-like structure, as a result of the following steps of the method: cooling a liquid metal inside a volume to cause the formation of primary intermetallic phases, in particular an α-Alx(Fe,Mn,Cr,Cu)ySiz intermetallic phase; rotating the cooling mould during the solidification process; heating the outer walls of the crucible or mould heated at the same time as the cooling (solidification) process is carried out, where heating can be achieved either by electrical resistance, induction or gas burners. |
