ANALYSIS OF MICRO MILLING CUTTING PARAMETERS & TOOL WEAR OF TITANIUM ALLOY (TI-3AL-2.5V) MACHINING

Abstract

With exigent demand, and requirement of miniature products in medical, aerospace, and electronic industry, it is growing need to introduce new low cost, high quality, and high accuracy process capable of producing miniature products. Despite of many advantages and very suitable process for miniature devices, there are still some challenges in micro- milling. Formation of burr is one of the major problems which is being faced in micro milling. Extensive research has been conducted to minimize its formation. Titanium alloys possesses excellent properties which make them first choice for medical & aerospace applications. Titanium grade-5 (Ti-6Al-4V) alloy abounds in literature for most of the applications but there are some applications, where due to excellent properties of titanium grade 9 (Ti-3Al-2.5V), it becomes an attractive choice for precision production applications i.e., pacemaker in medical and honeycomb in advanced aerospace applications. The current work in this research study aimed to analyze the influence of various process parameters of micro milling operation on the surface quality, burr formation and tool flank wear in micro machining of titanium grade 9. Three levels of each process parameter were taken into consideration. Process parameters were statistically analyzed by employing ANOVA (analysis of variance) for key process parameters. Results of this study show that feed rate is major factor influencing the surface roughness & burr formation with contribution ratio of 62.96 % & 54.05 % respectively, whereas cutting speed and depth of cut were also significant factors for surface roughness with contribution ratio of 20.32 % & 9.27 % while contribution of these two parameters for burr width stood at 21.63 % & 10.91% respectively. Cutting speed is major influencing factor for tool flank wear with contribution ratio of 54.02 % while feed rate contribution stood at 33.18 %. Depth of cut found insignificant factor for tool flank wear. Feed rate was only significant factor in length of burr with contribution ratio of 45.14%. Confirmation tests were conducted at optimum parameters which showed minimum value of burr width, length, surface roughness and tool flank wear.