Experimental investigation of high speed micro machining of H13 tool steel and titanium alloy 6-4

High-accuracy miniaturized components are increasingly in demand for various industries such as aerospace, biomedical, electronics, environmental, communication and automotive, and this coupled with new developments of High Speed Machining (HSM) has led to the emergence of a strong and viable technology in High Speed Micro Machining. This technology is very important in bridging the macro-domain and the nano- and micro- domains for making functional miniaturized components. High speed Micro Machining is a specific technology where high spindle speeds, high performances cutting tools and high accuracy control systems are used. The understanding of this technology is still not well established and theories are still under development. A major implication of the High Speed Micro Machining process is the relatively high machining forces with respect to the cutting tool's size, which often cause low process reliability and high costs, due to frequent tool failures and short tool life. The aim of this investigation is to contribute towards a fundamental understanding of the effects of increased spindle speed in High Speed Micro Machining

The impact of high speed machining on computing and automation

Machine tool technologies, especially Computer Numerical Control (CNC) High Speed Machining (HSM) have emerged as effective mechanisms for Rapid Tooling and Manufacturing applications. These new technologies are attractive for competitive manufacturing because of their technical advantages, i.e. a significant reduction in lead-time, high product accuracy, and good surface finish. However, HSM not only stimulates advancements in cutting tools and materials, it also demands increasingly sophisticated CAD/CAM software, and powerful CNC controllers that require more support technologies. This paper explores the computational requirement and impact of HSM on CNC controller, wear detection, look ahead programming, simulation, and tool management

A review of the application of acoustic emission technique in engineering

The use of acoustic emission (AE) technique for detecting and monitoring damages and the progress on damages in different structures is widely used and has earned a reputation as one of the most reliable and well-established technique in non-destructive testing (NDT). Acoustic Emission is a very efficient and effective technology used for fracture behavior and fatigue detection in metals, fiberglass, wood, composites, ceramics, concrete and plastics. It can also be used for detecting faults and pressure leaks in vessels, tanks, pipes, as well as for monitoring the progression of corrosion in welding. This paper reviews major research developments over the past few years in application of acoustic emission in numerous engineering fields, including manufacturing, civil, aerospace and material engineering

Developing a Construction Occupational Safety and Health Risk Assessment Matrix (COSHRAM) with modifying risk factors

Common Risk Assessment Matrix (RAM) is universal and can be apply in any industries. The aims of this paper is to develop a Construction Occupational Safety and Health Risk Assessment Matrix (COSHRAM) which can ideally improve the risk action plan. A new element of modifying factors has been incorporated to systematically justify the residual risks. The COSHRAM was developed on the basis of historical accident data and data collected from the field survey. Six (6) Safety and Health Officer (SHO) divided into three (3) groups were selected to conduct field trials. Each group has conducted risk assessment using both common RAM and COSHRAM. Overall, three (3) types of activities, including twenty-one (21) sub-activities and fifty-nine (59) hazards have been evaluated. Paired t-test showed that result of the assessment between the common RAM and COSHRAM was significantly different (t=17.083, p < 0.05). Therefore, the COSHRAM is statistically acceptable and it resulted in better in terms of estimating the risks than the common RAM

The effect of forming parameters on the sheet stretch in incremental sheet forming (ISF) process on CNC lathe machine

The effect of forming parameters during the incremental sheet forming process (ISF) was studied for a circular shape sheet part. ISF is known as a rapid prototyping method to pro-duce sheet metal parts in a batch production series. ISF has found to be useful and advantageous which increases its application in industry. A CNC lathe machine was used in this study because it was easily programmed to move an indenter which worked as the tool, through the sheet metal which was clamped on a plain rounded mold. The work also investigated the influence of some process variables such as spindle speed, tool material; tool feed rate and temperature during the forming procedure. The results showed that a proper spindle speed and tool feed rate at some stage in the forming process improved the surface quality and the rate of penetration

Analysis on tool life and surface characteristic in milling Stavax Supreme material

Stavax Supreme material is classified as difficult-to-machine material. The difficulty does not preclude the use of this material, especially in the mold industry. In this experiment, high speed end milling of Stavax Supreme (52 HRC) was investigated using five different types of tool. Performance of the cutting tools was compared with respect to tool life and surface roughness of the workpiece. Machining process was conducted in two parameters where each parameter used different rotation spindle speed and feed rate but same chip per tooth removal rate. The best cutting performance was obtained with TiN and TiCN. TiAlN tool also proved to be suitable for high speed end milling of Stavax Supreme but for finishing process only because fast tool wear in high spindle speed. The Xceed coated tool is more suitable for roughing process only in high spindle speed

Development of an integrated grating and slicing machine for starchy vegetables

Processed foods usually undergo one or several unit food processing operations before becoming the final products. Many food processing equipments were developed to perform more than one operation in food processing by providing practical purposes that further enhance their performance. However, conventional processes of grating and slicing that produce grated and sliced food products normally involved two units of independent operation machines. Therefore in this study, grating and slicing processes have been combined into a single operation through an integrated machine for simultaneous grating and slicing operations. The purpose of integrating both grating and slicing processes is to increase productivity through the reduction of cost, time and the number of unit operations, which are involved in the processing system of grating and slicing production. The machine’s design specifications were identified to ensure that simultaneous grating and slicing operations in an integrated machine are capable to process the raw materials (starchy vegetables) simultaneously for grated and sliced outputs. A final machine design was generated by following a product development process as the research method. The design process steps starts from planning, concept development, detail design and machine fabrication, testing and refinement. The final design of the machine (at present) shows that it is suitable for use in industrial processing level which the output rate is powered at 750 W with variable speed of 0 – 180 rpm, grated and sliced production range of 750 – 1200 kg/h and 250– 400 kg/h, respectively. This newly designed machine is easy to setup, handle, store, clean, service and maintain. The design of an integrated grating and slicing machine will express a better understanding on the machine capability to reduce cost and energy for simultaneous grating and slicing processes with increased productivity

A review of processing and machinery for Jatropha curcas L. fruits and seeds in biodiesel production: harvesting, shelling, pretreatment and storage

The harvested Jatropha fruits need to be cleaned, dehulled and stored properly as part of the production of Jatropha biodiesel. During processing, the oil yield and quality of the extracted crude oil can be further improved by removing the husks (outer coating) of the seeds before any necessary seed treatment. This report attempts to provide an insight into the major issues of the process from harvesting the Jatropha fruits to the final storage of the seeds and pretreatment of the Jatropha seeds prior to the oil extraction process in production. This report describes a few aspects of the processes including common methods, research and technologies involved so that some improving strategies can be devised. The final part of this report also describes current development trends and the future prospect of Jatropha as a biodiesel. The paper has determined that both the harvest and shelling processes are basically performed manually, especially in rural areas. These activities are time consuming and introduce a high labour cost (80% of the feedstock cost) that can potentially make the Jatropha oil economically uncompetitive. A solution consisting of process mechanisation and mechanical device development are proposed to improve the sustainability of the industry and to meet the increasing world demand. An improvement in oil yield can also be achieved by fruit/seed pretreatment such as drying, shelling and heating. However, improper control may lead to the formation of oxidation products such as free fatty acids which will affect the efficiency of biodiesel production. This is an important sustainability issue which is related to the future development of Jatropha biodiesel

Effect of process parameters on the surface roughness of aluminum alloy AA 6061-T6 sheets in frictional stir incremental forming

Incremental Sheet Forming (ISF) is characterized by essential flexibility, great formability, and low forming forces and cost compared to the conventional sheet metal forming processes. ISF was born as an advance sheet metal forming process to perfectly fit previous requirements. Nevertheless, growing demand to apply the lightweight materials in several fields was placed this developed process in a critical challenge to manufacture the materials with unsatisfied formability especially at room temperature. Thus, utilizing the heat at warm and hot condition in some ISF processes has been introduced to solve this problem. Among all heat-assisted ISF processes, frictional stir-assisted Single Point Incremental Forming (SPIF) was presented to deal with these materials. In this work, this emerging process was utilized to manufacturing products from AA6061-T6 aluminum alloy. Experimental tests were performed to study the influence of main parameters like tool rotation speed, feed rate, step size and tool size on the surface roughness of the produced parts. A Taguchi method and varying wall angle conical frustum (VWACF) test were used in the present work. The results find that tool diameter has a significant impact on the internal surface roughness produced via the forming process with a percentage contribution of 93.86 %. The minimum value of the surface roughness was 0.3 µm

Incremental sheet forming (ISF) of AISI 316 stainless steel sheet using CNC milling machine

Incremental sheet forming (ISF) is a method to form a sheet metal into desired shape and surface features in a batch production series. This method includes forming a clamped sheet metal in controlled conditions by a CNC milling machine, lathe machine or a robot. In this study, the effects of forming parameters on the amount of stretch in stainless steel sheet using a CNC milling machine have been investigated. A ball-point shaped tool made of a bronze alloy was fabricated and used throughout the experiments. The tool acted as the indenter that formed the stainless steel sheet into a small pyramid-like shape. The results showed that as the spindle speed and feed rate increased, the amount of sheet stretch also increased, up to a point where the sheet could not stretch anymore and the process changed from forming to shear thinning and chipping. In addition, the surface quality of the part was badly affected at higher spindle speed and feed rate settings. The temperature of the lubrication oil was also measured during the process and the maximum temperature recorded was 45°C which remained constant until the end of the process. In conclusion, to obtain a good quality part while increasing the productivity of ISF, the optimized values of the feed rate and spindle speed in this work were found to be at 500 mm/min and 1000 rpm respectively