Res-AlMA - Recycled Aluminum in Marine Applications

Østlandske Lettmetall is involved in several projects, with new products for the maritime market. Common requirements for the most curative products are mechanical properties and a stable geometry with tight tolerances. The production process is based on the machining of components from thick aluminum plates. Specific to thick plate as starting material, there are inherent residual stresses which are critical for dimensional stability, and consequently tolerance requirements for a product. Residual stresses can also occur in the individual process steps. Before the start of the project, quality control in the company's production process was based on checking products that resulted in scrap or acceptance. The whole process was to some extent characterized by over-consumption of both input material, energy and time per product. The aim of the project is to facilitate the achievement of product requirements and make the production process more efficient. One direction in the project is to streamline the production of components machined from thick aluminum plates with a primary focus on reducing residual stresses in the material through optimization of hardening processes. The other direction is to establish a more environmentally friendly production process where, through casting of scrap metal to "near product geometry", the number of process steps will be reduced, and unnecessary material waste through the machining process will be avoided. In addition, work is being done to improve quality control, which requires a transition from product control to process control. The project started with an initial mapping and measurement of residual stresses in the material along the entire process chain using standardized hole-drilling and contour methods. Experimental results in combination with finite element analysis enabled the development of a hybrid numerical-experimental method for accurate mapping of the residual stresses in both lab scale and production line. With this work, the critical steps in the production process were uncovered, which are the biggest sources of rebuilding residual stresses in the material. Well-planned experiments with varying process parameters resulted in improved or new work processes and methods that can be, or are already, implemented at the company. The main goal here was to significantly reduce residual stresses in the material and at the same time ensure a positive effect on the product's dimensional stability and product performances. To be able to start with the experiments aimed at establishing the more environmentally friendly production process based on casting of scrap metal to "near product geometry", it was necessary to carry out an improvement of the existing casting procedure. An in-situ hydrogen monitoring and numerical simulation of the casting process has resulted in a significant improvement in product quality. One of the project's sub-goals is a better and systematic process control which should, in the long term, result in better process control and consequently a reduction of total scrap. During the project period, a framework was established for real-time process data follow-up and collection to facilitate process optimization and product traceability and quality.

Res-AlMa foreslås som et 3-årig Innovasjonsprosjekt i næringslivet, med Østlandske lettmetall AS (ØL) som prosjekteier. ØL er en bedrift med stort vekstpotensial, som ser muligheter for omstilling til produkter utenfor petroleumssektoren. En slik omstilling betinger at det utarbeides nye løsninger for å møte kravene fra nye kundesegment. Gjennom Res-AlMa ønsker ØL, i samarbeid med bedrifts- og forskningspartnere, å skape nye løsninger som vil sikre en god posisjon i et krevende marked. Bedriften er en ny bruker av IPN ordningen. Skipsverft og komponent-leverandører til skipsverft har tidligere hatt en overvekt av leveranser til offshore-industrien. I de senere år har imidlertid skipsverftene og skipsbyggere fått en mer variert produktportefølje, med økende andel leveranser til havbruksnæringen, passasjer/cruise-båter, ferger og vindfartøy. For å sikre seg en god posisjon på de krevende markedene er det viktig å kunne tilby skreddersydde komponenter med riktige egenskaper til en konkurransedyktig pris. I dette prosjektet ønsker vi å utvikle en ny, innovativ produksjonsprosess for lettere, robuste komponenter i resirkulert aluminium til passasjer-skip (elektriske ferger) samt fiske- og oppdrettsindustrien. Komponenter med redusert vekt vil gi lavere energi-forbruk og, ved fossilt brensel, CO2-utslipp. Samtidig vil bruk av resirkulert metall som utgangspunkt for komponentene bidra til reduksjon av det totale miljømessige fotavtrykket. Med produksjonsprosess vi foreslår vil vi oppnå høyere grad av kontroll av hvert prosess-steg samt en total reduksjon i antall steg i prosessen. Prosessen vil resultere i komponenter med mer konsistent kvalitet, og være mer material og tids-effektiv. Innovasjonen vil hjelpe prosjekteier i å øke produksjonskapasitet i allerede eksisterende utstyr. Realisering av innovasjonen krever intensiv forskningsinnsats fra bedriftspartnerne (Østlandske Lettmetall, Metalco og Molstad), samt komplementær forskningsinnsats fra forsknings-partnerne.