Experimental investigation on micromilling of oxygen-free, high-conductivity copper using tungsten carbide, chemistry vapour deposition and single-crystal diamond micro tools

Insufficient experimental data from various micro tools limit industrial application of the micromilling process. This paper presents an experimental comparative investigation into micromilling of oxygen-free, high-conductivity copper using tungsten carbide (WC), chemistry vapour deposition (CVD) diamond, and single-crystal diamond micromilling tools at a uniform 0.4mm diameter. The experiments were carried out on an ultra-precision micromilling machine that features high dynamic accurate performance, so that the dynamic effect of the machine tool itself on the cutting process can be reduced to a minimum. Micromachined surface roughness and burr height were characterized using white light interferometry, a scanning electron microscope (SEM), and a precision surface profiler. The influence of variation of cutting parameters, including cutting speeds, feedrate, and axial depth of cut, on surface roughness and burr formation were analysed. The experimental results show that there exists an optimum feedrate at which best surface roughness can be achieved. Optical quality surface roughness can be achieved with CVD and natural diamond tools by carefully selecting machining conditions, and surface roughness, Ra, of the order of 10nm can also be obtained when using micromilling using WC tools on the precision micromilling machine.EU FP6 MASMICRO projec

Investigation of a scale-up manufacturing approach for nanostructures by using a nanoscale multi-tip diamond tool

Increasing interest in commercializing functional nanostructured devices heightens the need for cost-effective manufacturing approaches for nanostructures. This paper presents an investigation of a scale-up manufacturing approach for nanostructures through diamond turning using a nanoscale multi-tip diamond tool (four tip tool with tip width of 150 nm) fabricated by focused ion beam (FIB). The manufacturing capacity of this new technique is evaluated through a series of cutting trials on copper substrates under different cutting conditions (depth of cut 100–500 nm, spindle speed 12–120 rpm). The machined surface roughness and nanostructure patterns are measured by using a white light interferometer and a scanning electron microscope, respectively. Results show that the form accuracy and integrity of the machined nanostructures were degraded with the increase of the depth of cut and the cutting speed. The burr and the structure damage are two major machining defects. High precision nano-grooves (form error of bottom width < 6.7 %) was achieved when a small depth of cut of 100 nm was used (spindle speed = 12 rpm). Initial tool wear was found at both the clearance cutting edge and the side edges of tool tips after a cutting distance of 2.5 km. Moreover, the nanometric cutting process was emulated by molecular dynamic (MD) simulations. The research findings obtained from MD simulation reveal the underlying mechanism for machining defects and the initialization of tool wear observed in experiments

Turning the world upside down: Developing a tool for training about SM

About the book: Psychological and medical perspectives on sadomasochism (SM) have historically been concerned with understanding it as a form of psychopathology. In the past (but still often today) studies of SM have been concerned with extreme and most often non-consensual acts. More recently, however, there has been growing interest in exploring the meaning of sadomasochism in non-pathological ways. Safe, Sane and Consensual includes work from across the social sciences exploring a variety of aspects of SM from a non-pathological perspective. There are discussions of the history and culture of SM, medical and legal understandings, along with theory and original research on the topic. There are also sections on SM and psychotherapy and writing on bridging the academic/activist divide. The book includes contributions from an international group of academics, practitioners and activists and represents some of the most recent cutting edge work in the field by leading scholars

Method of determining the process applied for feature machining : experimental validation of a slot

In this paper, we will be evaluating the "manufacturability" levels for several machining processes of "slot" feature. Using the STEP standard, we will identify the slot feature characteristics. Then, using the ascendant generation of process method, we will define the associated milling process. The expertise is based on a methodology relative to the experience plans carried out during the formalization and systematic evaluation of the machining process associated with the feature

The development of an incremental debugging system : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Computer Science at Massey University

Debugging is a major area of software development that has received little attention. This thesis starts by looking at work done in the area of bug prevention, bug detection, bug location and bug correction. A debugging system, BIAS, is proposed to help in detecting, locating and correcting bugs. Three major design goals are established. Firstly, the system should be simple and easy to understand as this will encourage use. Secondly, the system should be general so that it will be available to a large number of users. Finally, it should be incremental as this will save users' time. An incremental language, STILL, is designed to show how BIAS applies to structured languages. The construction of the system is shown. Each data structure, and how it is used, is described. BIAS uses an interpretive system and runs threaded code on a pseudo-machine. How the threads are interpreted and how they are set up is shown next. The use of BIAS is shown by following through an example session with the system. This consists of entering a program, editing it, and running it. As bugs show themselves, various debugging commands are used to locate the bugs. The program is then edited, and the corrections linked into the code so that it will run correctly. This cycle is repeated until no bugs remain, without at any time recompiling the whole program. It turns out that the best way of achieving the design goals is to extend an incremental compiler host to include debugging commands. This gives a clear emphasis to the power of incremental compilers

The fabrication of beryllium. Volume III - Metal removal techniques

Metal removal techniques for beryllium in spacecraft structure applicatio

Study of burr formation and phase transformation during micro-milling of NiTi alloys

Micro-milling can be defined as milling with end mills smaller than 1 mm of diameter. The top-down approach from milling to micro-milling is often used to define cutting conditions. Unfortunately geometries either for the active part or the overall shape are quite different from conventional tools, leading to inexistent problems at the macro-scale, such as a larger cutting edge radius to uncut chip thickness ratio leading to ploughing effect. Moreover, micro-milling can be used on particular material such as shape memory alloys in biomedical domain which are difficult to machine. This study focuses on burr formation during shoulder milling for two biocompatible NiTi alloys: a martensitic NiTi (shape memory effect) and an austenitic one (pseudo-elasticity effect). Design of experiment is used to highlight the influence of various parameters (cutting parameters and material phases) on the burr formation in micro-milling NiTi alloys. Burrs were observed and measured using confocal, optical and electronic microscopy and tend to be as large as shoulders dimensions. Material phase transformation was also examined. Analysis of variance emphasizes that the larger the feed per tooth and the smaller the width of cut are, the smaller the top burr is. Cutting strategy leads to different burr shape: up-milling burrs have a large curvature, whereas down-milling burrs are slightly bent. An affected layer of about 10 μm has been observed for the austenitic NiTi. The proposed experimental approach give the opportunity to study burr formation in micro-milling, the machinability of alloys or superelastic NiTi shape memory and a qualitative explanation of burr formation has been developed

Spoken Stories, Spoken Word: An Insurgent Practice for Restorative Education

This paper uses the terminology of whiteness, settler colonialism, culturally responsive pedagogy, and restorative education to interrogate the usage of spoken word in schools. I argue that spoken word can function as a form of resistance to white colonialist practices and as an advocate of emotional learning and critical education. This paper focuses on representation, student empowerment, and identity exploration in the context of education institutions. It crosses borders between education and authenticity, between classrooms and real life, and between teachers and students. I aim to ground this essay in the American Studies discipline as it discusses systems of power in the United States and seeks to disrupt dominant narratives through spoken word as an alternative education strategy for dismantling white supremacy and validating marginalized identities. This work is only a small part of the larger conversation on restorative justice in education