A Six Sigma Approach for Precision Machining in Milling

• Published in: Procedia engineering Vol. 97; pp. 1474 - 1488
• Main Authors: Nithyanandam, Ganesh Kumar, Pezhinkattil, Radhakrishnan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2014
• Subjects: DOE; Machining; Milling; Process variation; DOE; Process variation; Machining; Milling
• ISSN: 1877-7058; 1877-7058
• DOI: 10.1016/j.proeng.2014.12.431

Controlling the process variations on the perimeter of a component to the targeted mean in milling is a huge challenge. Several factors such as spindle speed, feed rate, depth of cut, etc. affects this process variation. In this paper, spindle speed and feed rate are considered. Aluminum alloy 6061 widely used materials in aircraft, automobile and helicopter components is selected for this study. A full factorial design of experiment is carried out with five levels. Three different machining conditions: machining 2mm thickness, machining 3mm thickness and machining 4mm thickness are considered. The objectives of the study are: (a) to determine the optimum cutting parameters to minimize the process variations found on the perimeter of the work piece;’ (b) to determine which machining condition provides least process variations. To achieve this, 25 different combinations of experiments are conducted under each machining condition. Thus, a total of 75 experiments are carried out. Non-contact laser detection system is used to collect the real-time machining data. Two-way ANOVA is used to analyze the data. The results found that (a) both spindle speed and feed rate are significant over the process variations on the perimeter of a component; (b) feed rate is more significant on the outcome when compared to spindle speed; (c) process variations found on the perimeter of the component size 2mm thickness are more when compared to a component size 4mm thickness; and (d) mathematical models are derived for determination of optimum cutting parameters to achieve tighter process variations.