Papers by Keyword: AlTiC

Abstract: Pin-on-disk technique was used as a tool to study the tribological properties of contacting surfaces of alumina-titanium carbide composite material and diamond slicing blade. Conditions for testing are linear sliding speed between 0.2 and 0.4 m/s under applied load of 10 N and sliding distance up to 5000 m. The physical properties of both specimens which are mass loss, surface roughness and morphology of worn surface are investigated. The effect of linear sliding speed is analyzed in term of friction coefficient, surface roughness, and specific wear rate. It was found that, at initial state of wear, when sliding distant is less than 1000 m, the wear is severe, as seen by high values of specific wear rate and large fluctuation of friction coefficient. Worn surface of AlTiC is rougher than as-received condition. For a longer sliding distant, milder abrasion is found, as seen by the lower specific wear rate, and less fluctuation of friction coefficient, which produces worn AlTiC surface which is smoother than the as-received condition.

Abstract: Alumina-titanium carbide composite (Al₂O₃-TiC) is one of advance ceramic matrix composites (CMC) that have been used in machining tool and tribology application because of its excellent mechanical properties. Powder processing is often a chosen method to produce this family of material, i.e. hot pressed (HP), hot iso-static pressed (HIP), and pressure-less sintering (PS). These manufacturing techniques convert sub-micron powder into dense bulk component. Al₂O₃-TiC composite has been prepared by HIP process, containing 65%vol Al₂O₃ and 35%vol TiC. The powders were pressured and sintered at temperature between 1250˚C - 1650˚C. Thermal residual stress from Al₂O₃-TiC manufacturing process is conventionally unavoidable. The aim of this study is to investigate the microstructure of HIPped Al₂O₃-TiC composite and its residual micro-strain using transmission electron microscopy (TEM) with selected area electron diffraction pattern (SADP) analysis. The Al₂O₃-TiC composite was prepared by high-precision machining/grinding processes then focus ion beam milling process was used to section the TEM lamella. Microstructures, grain size and phases were determined by TEM and X-ray diffractometry (XRD). Micro-strains of {200}TiC, {111}TiC , {220}TiC and {012}Al₂O₃ were investigated by SADP (Selected Area Diffraction Pattern). Our result revealed there is approximately 0.01 compressive strains distributed in Al₂O₃-TiC composite.

Abstract: AlTiC master alloys have been prepared by Contact Reaction Method（CRM）.X-ray diffraction，SEM and EDS were used to analyse the AlTiC master alloys. It showed that morphology and distribution of TiC and Al3Ti particle have correspondingly changed with the transformation of temperature. As a result, the change in morphology and distribution of TiC and Al3Ti particle has considerably affected the gain refining performance of AlTiC master alloys. The result showed that it had excellent grain refining performance for commercially pure aluminum in 800°C.

Abstract: AlTiC master alloys have been prepared by Contact Reaction Method（CRM）.X-ray diffraction，SEM and EDS were used to analyses the AlTiC master alloys. It showed that morphology and distribution of TiC and Al3Ti particle have correspondingly changed with the change of the size of powder. As a result, the change in morphology and distribution of TiC and Al3Ti particle has considerably affected the gain refining performance of AlTiC master alloys. The result showed that: when the grain size of Ti is much smaller, the effect of refinement is much better.

Abstract: The AlTiC master alloy has been prepared in different components to refine 99.8%Al and 99.98％Al, then compared to two typical Al5Ti1B in refining efficiency and the grain nuclear. The result showed that the refining efficiency seemed better if the nucleation of high pure aluminum revealed complexity and variety. It may due to that the latency heterogeneous nucleation was efficient on the whole, consequently accelerated refining efficiency.