AbstractMachining difficult-to-cut materials such as titanium Ti-6Al-4V, hypoeutectic and eutectic aluminium alloys, Inconel 718 and austenite-ferrite super duplex 2507 are usually accompanied with low productivity, poor surface quality and often short tool life. Despite their increased usage in the aerospace, automotive and nuclear industries, manufacturing facilities are constantly faced with slow production and high manufacturing costs due to the incorrect selection of cutting tools for these materials. However, manufacturing facilities are not to blame for some of the causes of slow productivity.
There are numerous designs of cutting tools currently available in the metal cutting market but are either generic or not specific to the operation, expensive, or only cover a range of materials such as stainless steels. Extensive research has mainly been conducted on machining parameters, coated tungsten carbide inserts, coating technologies and insert tool geometry optimisation, mainly for turning. The continuous development and advancements in tool materials and coating technologies have provided improvements in tool life and productivity for machining difficult-to-cut materials. However, critical factors, including tool geometry are usually missed. Tool design and tool geometry are one of the few critical factors considered when machining difficult-to-cut materials. Cutting tool geometry in end-milling and drilling is a topic which needs further understanding, to evaluate the effect of geometrical parameters in machining of difficult-to-cut materials. This research explores the effect of various cutting tool geometries on tool life and surface roughness in end-milling and drilling of difficult-to-cut materials.
Solid tungsten carbide with cobalt binder cutting tools are commonly used in metal cutting due to their capabilities of enduring high stresses and withstanding heat at the tool-chip interface. Understanding tool geometry and its effect on difficult-to-cut materials can provide a solution to improving tool life, productivity and reducing costs in manufacturing environments. The aim of this research is to investigate the effect of tool geometry on four selected difficult-to-cut materials in end-milling and drilling operations to enhance their performance. A detailed research study, exploring the effect of tool geometry in end-milling and drilling of difficult-to-cut materials was carried out. A methodology was developed for designing and optimising solid tungsten carbide (WC) end-mills and drills. A total of 10 cutting tools, 5 end-mills and 5 drills, were designed and tested to determine a relationship between tool geometry and tool life. Results indicated that using a correct tool geometry can improve tool life and surface finish.
|Date of Award||19 Jun 2019|
|Supervisor||Alborz Shokrani Chaharsooghi (Supervisor) & Stephen Newman (Supervisor)|