摘要:
The aim is to improve the strength of an intermetallic bond between engine component made from an aluminium alloy and a reinforcing element made from austenitic cast iron. For that purpose, the reinforcing element is annealed in a decarbonising atmosphere before the known prior art alfin process is carried out, in order to obtain an alfin layer largely free of graphite scales.
摘要:
A method of centrifugally casting a composite tubular product comprised of an outer alloy layer (15) and at least one inner alloy layer (16) while substantially inhibiting the formation of a metallurgical bond between layers in the final casting. The product is produced using a rotatable centrifugal casting mold having a cylindrical inner surface adapted to receive a molten metal alloy. The outer layer (15) of an alloy having a melting point of at least about 1300 DEG C is poured into the rotatable mold. The outer layer (15) is solidified and cooled to a temperature not exceeding about 92 % of its absolute melting point before pouring of the least one inner layer (16) having a melting point of at least about 1300 DEG C. The composite casting may then by mechanically hot worked, such as by hot extrusion, to produce a composite tube in which the layers are metallurgically bonded to each other.
摘要:
A bearing material consists of a matrix of a metal alloy forming a monotectic system with Pb-based materials and substantially bead-shaped soft phases of a Pb-based material dispersed therein in such a way that the concentration of the soft phases increases in the matrix towards a surface of the bearing material. It is made by casting a melt containing in the mixture alloying components which form a monotectic system with Pb-based materials and alloying components which form a Pb-based material on a substrate in such a way and thus by setting the material thickness, the cooling conditions and the composition of the melt in such a way that the Pb-based material separates in the liquid state from the rest of the melt under the force of gravity and is concentrated in dispersed fashion in the lower region of the material.
摘要:
A method of forming a composite article having a first and a second metal component, and a resultant composite metal article, wherein a flux coating is applied over at least a substantially oxide-free bond surface of the first component, the first component with said flux coating is preheated and, with said first component positioned in a mould to fill a portion of a cavity of the mould, a melt for providing the second component is poured into the mould so as to flow over said bond surface; the first component being preheated to a first temperature and the melt being poured at a second temperature such that, on flowing over the bond surface, the meld displaces said flux coating and wets said bond surface, and that such initial temperature equilibration between said surface and the melt results in an interface temperature therebetween at least equal to the liquidus temperature of the melt, thereby resulting on solidification of the melt in attainment of a bond between the components.
摘要:
Es wird ein Verfahren beschrieben, bei dem ein Werkstück, beispielsweise ein Motorblock mit einer leicht gießbaren Aluminium-Legierung gegossen wird und anschließend zur Erhöhung der Verschleißfestigkeit zumindest teilweise in Randschichten nachbehandelt wird. Die Nachbehandlung besteht darin, die Randschicht mit einem härtenden Matertial, z.B. Silizium zu bestreichen und anschließend beispielsweise mit einem Laserstrahl aufzuschmelzen, so daß das härtende Material in die Randschicht gelangt.