IMPURITIES IN AL-5TI-1B (WT.%) GRAIN REFINER ROD

摘要

A “standard” and a “poor” Al-5Ti-1B (wt.%) grain refiner rod have been examined using computed tomography (CT) and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray (EDX) spectrometer. The refining potency of each rod was checked using the TP1 test. CT and SEM results from the “poor” refiner rod revealed the presence of Al3Ti agglomerates and spent salts. These findings are indicative of an inefficient, non-optimal manufacturing process. Results from the TP1 test showed the “standard” rod to be more effective in promoting refinement, as expected. The quality of the grain refiner rod used in industrial practice is therefore vital as the grain size, feedability, cleanliness, uniformity of microstructure and integrity of the as-cast part may all be deleteriously affected. Moreover, a well controlled manufacturing process is important for the production of cleaner grain refiner as this can indirectly improve the quality of castings.