Bøger af A K M Nurul Amin

Chatter is an unwanted phenomenon in machining due to its adverse effects. Chatter control is difficult in the absence of unified understanding on the causes of chatter formation. This book presents experimental results contesting the validity of the established Regenerative Chatter theory and proposes a resonance based chatter theory. The authors have proved based on extensive chip analysis that chip formation in turning thread cutting and end milling of metals and alloys is accompanied with the formation of primary or secondary serrated teeth with frequencies that increases with cutting speed. The analysis of the vibration signals in frequency domain (FFT) on the other hand proved that chatter is the outcome of resonance and it appears in the system when the frequency of the serrated teeth become approximately equal to any one of the

Machining of single crystal silicon is a challenging and expensive affair due to the high hardness and inherent brittleness of the material. Major problem in conventional machining of brittle materials like silicon is the generation of cracks and subsurface damages. This book outlines a ductile mode machining process developed for silicon employing high speed end milling using diamond coated tools. The developed method was found to ensure integrity of the machined surface and good surface finish. The influence of the cutting parameters, such as, cutting speed, feed and depth of cut, on ductile mode machining are discussed in the book. A 3-level full factorial design of experiments using Response Surface Methodology (RSM) was employed to develop regression model of average surface roughness. The developed model was tested using Analysis of Variance (ANOVA) at 95% confidence level. The best average surface roughness achieved was 0.2¿m, which could alleviate the need for further grinding and rough polishing operations to save cost and cycle time of machining silicon.