Naslov
Continuous Casting of Cu-Al-Ni Shape Memory Alloys

Autori
Lojen, Gorazd ; Kneissl, Albert C. ; Gojić, Mirko ; Rudolf, Rebeka ; Čolić, Miodrag ; Anžel, Ivan

Izvornik
Livarski vestnik (0024-5135) 57 (2010), 4; 172-193

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Shape-memory alloys ; Cu-Al-Ni ; Continuous casting ; Microstructure ; Mechanical properties

Sažetak
Shape memory alloys, especially polycrystalline ones, have some disadvantages compared with the most used Ni-Ti alloys. The most important disadvantage is high brittleness, and consequently, smaller reversible deformation. But on the other hand, Cu-Al-Ni alloys have also some advantages: melting, casting, control of chemical composition and machining are less demanding, they have higher Young’s moduli, higher resistance to degradation of functional properties and better cost-to-effect ratio. But working of slabs and ingots into semi-products of smaller cross-sections, even hot working (brittle β intermetallic phase), is still work and time consuming and thus expensive since only a small degree of deformation without intermediate annealing is possible during the rolling or drawing process. Therefore, manufacturing semi-products of smaller cross- sections directly from melt could considerably lower the costs. In spite of that, no data on the high-productivity continuous casting process of small-cross-section of shape-memory-alloy rods or strips could be found in references. Our research should diminish this blank. In our first experiments Cu 13 % Al – 4 % Ni (mass fractions) shape-memory alloy was continuously cast with laboratory equipment for vertical continuous casting directly from the melting crucible. A graphite mould with diameter of 16 mm was applied and various combinations of casting parameters were tested. Average casting velocities were in the range from 250 to 625 mm per minute. Castability of the alloy appeared to be good with all the tested parameters. This paper presents also achieved surface qualities, microstructures and some mechanical properties of cast strands.

Izvorni jezik
Engleski

Znanstvena područja
Metalurgija

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