Processing, characterization and erosion wear response of Linz-Donawitz (LD) slag filled polypropylene composites

This article reports a study on the erosion response of polypropylene (PP) composites filled with micro-sized Linz-Donawitz (LD) slag particles. LD slag is a major solid waste generated in huge quantities during steel making. It comes from slag formers such as burned lime/dolomite and from oxidation of silica, iron etc. while refining the iron into steel in the LD furnace. In this work, composites with different LD slag content (0, 7.5, 15, 22.5, 30 wt%) in a thermoplastic PP matrix base are prepared by injection molding technique. The composites are characterized with regard to their density, porosity, micro-hardness and strength properties. Solid particle erosion trials, as per ASTM G 76 test standards, are conducted on the composite samples following a well-planned experimental schedule based on Taguchi design of experiments. An air jet type erosion test rig capable of creating reproducible erosive wear situations is used for this purpose. Significant process parameters predominantly influencing the rate of erosion are identified. The study reveals that the LD slag content and impact velocity in the composites are most significant among various factors influencing the wear rate.