The effect on usage of quarry dust suspension as coolant in drilling of titanium alloy

• Main Author: Kursus, Maisarah
• Format: Thesis
• Language: English; English
• Published: 2022
• Subjects: T Technology (General); TJ Mechanical engineering and machinery
• Online Access: http://eprints.utem.edu.my/id/eprint/26883/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=122212

In the aerospace field, titanium alloys are extensively used for the airframe and engine parts to improve aircraft fuel consumption. Drilling through these parts in a single-shot process to produce high quality holes is challenging. During drilling, high temperatures are generated owing to the friction between the cutting tool and workpiece. This phenomenon causes in rapid tool wear and the deterioration of the machined/drilled surface. With increased tool wear, the cutting tool loses its sharpness, leading to burr formation at the exit of the drilled hole. To reduce the temperature produced in the cutting zone, different types of cooling techniques during drilling have been used by researchers. However, limited studies have been found by utilizing the quarry dust suspension as coolant in the drilling process. Therefore, the main objective of this study is to investigate the effect of different concentrations of quarry dust suspension as coolant in drilling of titanium alloy. Before drilling, the thermophysical properties of quarry dust suspension, namely, thermal conductivity and viscosity, were investigated experimentally. The effects of different concentrations of quarry dust on surface roughness, thrust force, and burr formation were evaluated, and their machining performances were compared with those obtained using aluminium oxide suspension. Before the experiments, both suspensions were prepared by dispersing quarry dust and aluminium oxide particles into deionised water at various concentrations ranging from 0 wt% to 0.10 wt%. Results indicated that thermal conductivity and viscosity improved with increased concentration of quarry dust suspension. When 0.06 wt% quarry dust suspension was used, there were improvement by 51.1% and 0.5% on thermal conductivity and viscosity, respectively compared to deionized water. The lowest thrust force and surface roughness as well as the best hole quality also can be obtained by using 0.06 wt% of quarry dust suspension. Besides that, thrust force and surface roughness showed an improvement by 8.31% and 18.29%, respectively, compared with those of aluminium oxide suspension at the same concentration. The burr height formed at the drilled holes using 0.06 wt% of quarry dust was also lower than that formed with aluminium oxide suspension at the same concentration. These results demonstrated the capability of quarry dust suspension as coolant, which could be beneficial to the machining industries.