INTECIN   20395
INSTITUTO DE TECNOLOGIAS Y CIENCIAS DE LA INGENIERIA "HILARIO FERNANDEZ LONG"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Amorphous coatings obtained by cold Rolling
Autor/es:
M. PICHIPIL; F. SAPORITI; F. AUDEBERT
Lugar:
Santa Fe
Reunión:
Congreso; SAM - XIII Congreso IBEROMET; 2014
Resumen:
Amorphous Al-based alloys obtained by rapid solidification (RS) have high mechanical strength and good corrosion resistance higher than the same material in the crystalline state. These alloys can be obtained in an amorphous state by RS in thicknesses up to tens of microns which make those not suitable for applications as structural material. However its application is very promising as a surface material. In this work a preliminary study on coatings of amorphous ribbons Al88Ni8Y4 (% at) on an Al-1050 substrate prepared by cold rolling is presented. The ribbons were produced by RS using the "Melt Spinning" technique. The corrosion behavior of the alloy with different microstructures obtained by thermal treatment at temperatures associated with the different stages of the crystallization process was studied. The coatings were performed by a single rolling step with a reduction of 50% using ribbons in the amorphous state. The adherence obtained was good, no cracks or detachment of the coating was observed. The corrosion resistance on ribbons and the coating was studied using potentiodynamic polarization curves in NaCl-1M solution. All samples containing amorphous phase present passivation zone, on contrary the fully crystallized sample did not show pasivation zone. The corrosion potential of the thermally treated samples showed a shift towards cathodic potentials in the potentiodynamic curve respect to the corresponding to the amorphous sample. The coating showed surface defects such as slip bands and microcracks generated by the high degree of deformation applied by rolling. The potentiodynamic curve of the coating revel a similar behaviour to the ribbon sample with a microstructure composed by a-Al crystals precipitated in an amorphous matrix that has a large passivation zone, potential and pitting corrosions more anodic than the substrate material, the Al-1050. The results open a great expectation of the cold rolling application for generating high corrosion resistant coatings using amorphous metallic alloys.