Precision Polishing Techniques for Metal Molding Dies and Glass Forming Technology “Slumping Method”

Precision manufacturing techniques are required for the fabrication of small and large optical components in various fields. To prepare molding dies with highly precise geometric shapes and surface roughness that are used in certain molding processes, polishing techniques have been investigated for many materials. In this research, the polishing techniques used for a SUS310S stainless steel molding die for the glass forming technology “slumping method” were investigated. The surface roughness of the polished SUS310S molding die surface was below Rz = 120 nm (P–V), Ra = 20 nm after 35 h of polishing with 0.5% alumina polishing liquid under a pressure of 1.7 kPa. In addition, the centerless polishing machine was designed and manufactured to polish cylindrical molding die surfaces with same polishing conditions. As the result of using cylindrical molding dies that made by this centerless polishing machine, the surface roughness of the glass plate formed using the slumping method with the polished molding die was below Ra = 20 nm. These results indicate that the surface roughness of the molding die had a small effect on the glass plate surface formed using the slumping method

Micro-grooving on electroless nickel plated die materials

Master'sMASTER OF ENGINEERIN

Mirror Surface Finishing of Miniature V-grooves Using MCF (magnetic compound fluid) Slurry

秋田県立大学平成28年

Processing of Graphene/CNT-Metal Powder

In recent days, the demand for powder metallurgy components has increased due to unusual combination of properties. Carbon allotropes such as graphene and CNT are the novel material to enhance the properties of powder metallurgy component. However, processing of such materials is in infancy stage due lack of advance processing technique. This can be addressed through integration of several fabrication techniques to meet the industrial demands. The processing method and its important parameter will define the final property of the component. Such materials have found its applications in various fields like, sports, bio implants, aerospace and automobile sector

Tribological Comparison of Traditional and Advanced Firearm Coatings

The objective of this project is to find which type of coating has the best performance characteristics for finishing firearms. This is accomplished by measuring and comparing several performance characteristics, such as: adhesion, hardness, wear resistance, friction control, and corrosion resistance. Appearance is not a factor since any exterior coating that is flashy can be subdued or camouflaged with special purpose paints, which have proven durable enough for such purposes. Cost will not be a limiting factor for this experiment, but will be discussed in the conclusion as a secondary concern. This data will be used to identify the best coating for steel and aluminum firearm parts. The goal is to lengthen a firearm’s life cycle while increasing performance and reliability by applying the best coating

Mechanism of material removal in tungsten carbide-cobalt alloy during chemistry enhanced shear thickening polishing

The use of cemented carbides is ubiquitous in many fields especially for mechanical tooling, dies, and mining equipment. Surface finishing of cemented carbide down to atomic level has been a long-standing quest in manufacturing and materials community. For application of complex-shaped cemented carbide components, this work proposes a novel ‘chemistry enhanced shear thickening polishing’ (C-STP) process using Fenton’s reagent to obtain sub 10 nanometers finished polishing at a rate twice that of the conventional STP. This work offers quantitative insights into the influence of the concentration of Fenton’s reagent on the polishing performance. While the material removal rate was seen to be sensitive to the concentration, the surface roughness (Sa) was found to be insensitive to the concentration of Fenton’s reagent. The electrochemical experiments proved that Fenton’s reagent could effectively reduce the corrosion resistance of tungsten carbide-cobalt alloy. The characterisation of polished carbides using XPS and EDS revealed that the Cobalt binder gets removed preferentially during C-STP, which explains why the material removal rate during this technique becomes twice that of conventional STP. This study provides a promising method for high efficiency polishing of tungsten carbide-cobalt alloy parts with complex-shaped such as micro-dril

Synthesis, processing and mechanical characterization of Ti(C,N)-based cermets through the combination of colloidal and powder metallurgy techniques

Mención Internacional en el título de doctorEsta tesis contiene artículos de investigación en anexo.The main objective of this thesis is the processing by combining colloidal and powder metallurgy techniques in aqueous medium of Ti(C,N) based cermets and their mechanical characterization.Esta Tesis Doctoral ha sido realizada entre la Universidad Carlos III de Madrid y el Instituto de Cerámica y Vidrio, siendo financiada por el proyecto MAT-2012-38650-C02-01 “Diseño de la microestructura y la microarquitectura de materiales metal-cerámicos utilizando tecnologías coloidales y pulvimetalurgicas” (MITICO) y por una Beca FPI-2013 (BES-2013-065760) del Ministerio de Economía y Competitividad.Programa Oficial de Doctorado en Ciencia e Ingeniería de MaterialesPresidente: Antonio Javier Sánchez Herencia.- Secretario: Sophia Alexandra Tsipas.- Vocal: Raquel de Oro Calderó

Micromachining

To present their work in the field of micromachining, researchers from distant parts of the world have joined their efforts and contributed their ideas according to their interest and engagement. Their articles will give you the opportunity to understand the concepts of micromachining of advanced materials. Surface texturing using pico- and femto-second laser micromachining is presented, as well as the silicon-based micromachining process for flexible electronics. You can learn about the CMOS compatible wet bulk micromachining process for MEMS applications and the physical process and plasma parameters in a radio frequency hybrid plasma system for thin-film production with ion assistance. Last but not least, study on the specific coefficient in the micromachining process and multiscale simulation of influence of surface defects on nanoindentation using quasi-continuum method provides us with an insight in modelling and the simulation of micromachining processes. The editors hope that this book will allow both professionals and readers not involved in the immediate field to understand and enjoy the topic

Development of a high-speed high-precision micro-groove cutting process

A high-speed, high-precision chip formation-based micro-groove cutting process has been developed for cutting grooves in metals with nearly arbitrarily shaped cross-sections, which have widths and depths of a few hundred nanometers to a few microns, and lengths of tens of millimeters. A flexible tool, consisting of a single-point cutting geometry mounted on the end of a small cantilever, is moved along a workpiece surface while a constant cantilever deflection is maintained to apply a cutting load. Depth of cut for a given tool shape is determined by cutting load and workpiece material properties. A major advantage of the flexible tool concept is increased depth of cut precision. Furthermore, the use of a flexible tool enables the process to be robust against machine tool registration error, guide misalignment, and component inertial deflections. The process was implemented by fitting a 5-axis micro-scale machine tool with a specially constructed micro-groove cutting assembly. Early, experiments using diamond-coated AFM probes as tools demonstrated process viability up to cutting speeds of 25 mm/min and chip formation at the sub-micron scale. However, AFM probe geometries proved too fragile for this demanding application. High quality tools with improved cutting geometries were designed and fabricated via focused ion beam machining of single-crystal diamond tool blanks, and tool edge radii of 50 - 64 nm were achieved. The improved tools enabled well-formed rectangular grooves to be cut in aluminum at up to 400 mm/min with widths of 300 nm to 1.05 microns and depths up to 2 microns. Complex compound v-shaped grooves were also produced. Virtually no tool wear (less than 20 nm) was observed over a cutting distance of 122.4 mm. Small amounts of side burr formation occurred during steady-state cutting, and exit burr formation occurred when a tool exited from a workpiece. Parallel 1.05 micron wide grooves were controllably cut as close as 1.0 micron apart, and machining of intersecting grooves was successfully demonstrated. To better understand process mechanics including chip formation, side burr formation, and exit burr formation at the small size scale involved, a 3D finite element model of the process was developed. Validation with experimental results showed that on average the model predicted side burr height to within 2.8%, chip curl to within 4.1%, and chip thickness to within 25.4%. An important finding is that side burr formation is primarily caused ahead of a tool by expansion of material compressed after starting to flow around a tool rather than becoming part of a chip. Also, three exit burrs, two on the sides of a groove and one on the bottom of a groove, are formed when a thin membrane of material forms ahead of a tool and then ruptures as the tool exits a workpiece. Finally, conclusions about the process are drawn and recommendations for future work are presented