COBEM99

S18 Processos Mecânico-Metalúrgicos

Title:

INFLUENCE OF ABRASIVE AND SUBSTRATE ROUGHNESS ON ALUMINUM COATING PROPERTIES

Summary :

THERMAL SPRAY OF ALUMINUM IS WIDELY USED TO PROVIDE PROTECTION AGAINST OXIDATION AND CORROSION IN METALLIC STRUCTURES, OFFSHORE AND OIL REFINERY INSTALLATIONS. THERMAL SPRAY MAY BE OBTAINED VIA CONVENTIONAL OXYACETYLENE FLAME OR ELECTRIC ARC PROCESSES. THE OXYACETYLENE FLAME IS A LOW COST PROCESS AND HAS THE ADVANTAGE OF BEING OPERATIONALLY SIMPLE. SPRAYING BY ELECTRIC ARC INVOLVES SOURCES OF HIGHER TEMPERATURES AND USUALLY DELIVERS SUPERIOR ADHERENCE. IN EITHER PROCESS, SURFACE PREPARATION IS THE MOST CRITICAL STEP FOR A GOOD RESULT. COATING ADHESION QUALITY IS DIRECTLY RELATED TO THE CLEANLINESS AND ROUGHNESS OF THE SUBSTRATE SURFACE. GRIT BLASTING IS GENERALLY USED TO ROUGHEN THE SUBSTRATE SURFACE FOR BETTER MECHANICAL ADHESION OF THE COATING TO THE SUBSTRATE. THIS REPORT DESCRIBES THE INFLUENCE OF GRIT BLASTING PARAMETERS ON SURFACE ROUGHNESS AND ON BOND STRENGTH OF ALUMINUM COATING SPRAYED BY EITHER FLAME OR ARC PROCESSES. THE WORK FOCUS ON THE EFFECTS OF THE BLASTING ANGLE AND BLASTING DISTANCE ON THE SURFACE ROUGHNESS AND COATING ADHESION. TWO TYPES OF NON-METALLIC GRITS WERE USED FOR BLASTING: ALUMINA AND COPPER SLAG GRITS. RESULTS ARE PRESENTED AND DISCUSSED IN THE PAPER. IT WAS ALSO FOUND THAT COPPER SLAG GRITS, AS COMMERCIALLY AVAILABLE, ARE NOT RECOMMEND FOR USING AS ABRASIVE IN SURFACE PREPARATION. TO THERMAL SPRAY. KEYWORDS: THERMAL SPRAYING, SURFACE ROUGHNESS, GRIT BLASTING, ALUMINUM

Author :

Buschinelli, Augusto J.A
Freire, Fabricio
Paes, Marcelo Torres P.
Trevisan, Roseana Exaltação

Paper View :