A review on selective laser sintering/melting (SLS/SLM) of aluminium alloy powders: Processing, microstructure, and properties

https://escholarship.org/content/qt4h56k1ch/qt4h56k1ch.pdf

Advanced monitoring of machining operations

Review of in-situ process monitoring and in-situ metrology for metal additive manufacturing

Wire-feed additive manufacturing (AM) is a promising alternative to traditional subtractive manufacturing for fabricating large expensive metal components with complex geometry. The current research focus on wire-feed AM is trying to produce complex-shaped functional metal components with good geometry accuracy, surface finish and material property to meet the demanding requirements from aerospace, automotive and rapid tooling industry. Wire-feed AM processes generally involve high residual stresses and distortions due to the excessive heat input and high deposition rate. The influences of process conditions, such as energy input, wire-feed rate, welding speed, deposition pattern and deposition sequences, etc., on thermal history and resultant residual stresses of AM-processed components needs to be further understood. In addition, poor accuracy and surface finish of the process limit the applications of wire-feed AM technology. In this paper, after an introduction of various wire-feed AM technologies and its characteristics, an in depth review of various process aspects of wire-feed AM, including quality and accuracy of wire-feed AM processed components, will be presented. The overall objective is to identify the current challenges for wire-feed AM as well as point out the future research direction.

Wire-feed additive manufacturing of metal components: technologies, developments and future interests

Recent advances in modelling of metal machining processes

On The Measurement of Temperature in Material Removal Processes

Temperature on Flank Face of Cutting Tool in High Speed Milling

In this study, cutting performance of CBN tools and PVD-coated carbide tools in end-milling of hardened steel was investigated. In high-speed dry hardmilling, two types of CBN tools were applied: the CBN-rich type and an ordinary one. In the case of relatively low-speed milling, on the other hand, a few coated carbide tools were selected where four kinds of coating films, TiN, TiCN, TiAlN and multi-layered TiAlN/AlCrN, were deposited on the K10 and P30 grade carbide. The cutting performance was mainly evaluated by tool wear, cutting temperature, cutting force and surface roughness. In dry cutting of hardened carbon steel with the ordinary CBN tool, the cutting tool temperature rose rapidly with increase in cutting speed; and tool temperature reached approximately 850 °C at the cutting speed of 600 m/min. In the case of the CBN-rich tool, the cutting temperature decreased by 50 °C or more because of its high thermal conductivity. It is remarkable that tool wear or damage on a cutting tool was not observed even when the cutting length was 156 m in both CBN tools. In the case of coated carbide tools, the temperatures of TiN-, TiCN- and TiAlN-coated carbide tools rose as cutting proceeded because of the progress of tool wear, but that of TiAlN/AlCrN-coated carbide tool hardly rose due to little tool wear. When the base material was K10 grade carbide, tool temperature was lower than that of P30 with any coating. The tool flank wear depends considerably on hardness and oxidizing temperature of the coating film.

Cutting performance of PVD-coated carbide and CBN tools in hardmilling

The Temperature of a Single Crystal Diamond Tool in Turning

The temperature at the tool flank, which has an effect on the tool life and on the machined surface integrity, is measured using a two-color pyrometer with a fused fiber coupler. This pyrometer makes it possible to measure the temperature of a very small object without emissivity affecting the results. A CBN tool is used as the cutting tool. A high carbon chromium bearing steel, a chromium molybdenum steel and a quenched carbon steel are used as work materials. The temperature of the tool is highly affected by the cutting speed, but the influence of the depth of cut and the feed rate is not so great. In the cutting of the high carbon chromium bearing steel, the temperature is 800 °C at a cutting speed of 100 m/min and increases with the increase of cutting speed, reaching 950 °C at 300 m/min. There is a close relation between the tool temperature and the hardness of the work material. The influence of cutting speed on tool wear is considerable.

Takashi Ueda

Papers

On The Measurement of Temperature in Material Removal Processes

Temperature on Flank Face of Cutting Tool in High Speed Milling

Cutting performance of PVD-coated carbide and CBN tools in hardmilling

The Temperature of a Single Crystal Diamond Tool in Turning

Temperature Measurement of CBN Tool in Turning of High Hardness Steel