The following 5 papers were presented at the 11th International Conference on High Speed Machining (HSM 2014), Prague, Czech Republic

COMPARISON OF MACHINING INCONEL 718 WITH CONVENTIONAL AND SUSTAINABLE COOLANT

MM (Modern Machinery) Science Journal, December 2014

DOI: 10.17973/MMSJ.2014_12_201415

David Fernández, Virginia García Navas, Alejandro Sandá, Ion Bengoetxea

IK4-Tekniker, Advanced Manufacturing Technologies, Eibar, Spain

e-mail: david.fernandez@tekniker.es

Abstract  
The use of super-alloys, most of them Ni- or Ti-based, has significantly increased during the last decade. Industries such as the aerospace,energy or transport, use these kinds of materials due to their excellent properties that combine hardness, high temperature strength and thermal shock and corrosion resistance. These desirable material properties make these alloys extremely difficult to machine, since high values of temperature and shear forces are easily achieved and a quick cutting tool wear turns out to be an important process constraint. Thus, with the objective to overcome this phenomenon, several methods can be used; the most common one is to add large amounts of water-based or oil-based cutting fluids directly into the cutting zone. However, nowadays other less conventional fluids are also being studied with the aim of achieving a more ecological and efficient process in the machining of these difficult-to-cut materials. Examples of this are vortex cold air or cryogenic cooling, among others. In this study a comparison between different cooling methods in turning of Inconel 718 is presented, which is the most commonly used nickel based alloy in the industry. Tool life and workpiece surface finish has been analyzed in each case, searching the pros and cons of each cooling technique. The results reveal the possibility of replacing traditional pollutant cooling fluids by other more ecologically friendly alternatives 
 
Keywords: cryogenic, machining, inconel, turning
 
Adobe AcrobatDownload full version of the Paper (Adobe Reader Document, 2.7 MB)
 
______________________________________________________________________________________________________________________________


FINITE ELEMENT MODELING OF THE ORTHOGONAL MACHINING OF PARTICLE REINFORCED ALUMINUM BASED METAL MATRIX COMPOSITES

MM (Modern Machinery) Science Journal, December 2014

DOI: 10.17973/MMSJ.2014_12_201416

Usama Umer, Mohammad Ashfaq, Jaber Abu Qudeiri, Hussein Mohammed Abdalmonaem Hussein, Abdul Rahman Al-Ahmari

FARCAMT, Advanced Manufacturing Institute, King Saud University
Riyadh, Saudi Arabia

e-mail:uumer@ksu.edu.sa

Abstract

2D finite element models (FEM) are developed to simulate orthogonal machining of particle reinforced aluminum based metal matrix composites (MMC). The models predict cutting forces, chip morphology, temperatures and stresses distributions. The simulations were carried out by developing a fully coupled temperature displacement model. In contrast to the equivalent homogeneous material (EHM) methodology, a heterogeneous model is developed based on reinforcement particle size and volume fraction. This allows models to simulate the local effects such as tool-reinforcement particle interaction, reinforcement particle debonding. The interface between the reinforcement particles and the matrix is modeled by using two approaches; with and without cohesive zone elements. Similarly the chip separation is modeled with and without using a parting line. The effect of different methodologies on the model development, simulation runs and predicted results have been discussed. The results are compared with experimental data and it has been found that the utilization of cohesive zone modeling (CZM) with the parting line approach seems to be the best one for the modeling of MMC machining

Keywords: finite element models (FEM), metal matrix composites (MMC),
cohesive zone modeling (CZM)

Adobe AcrobatDownload full version of the Paper (Adobe Reader Document, 3,2 MB)

___________________________________________________________________________________________________________________________

HIPIMS COATED CARBIDES WITH HIGH ADHESIVE STRENGTH FOR HARD MACHINING

MM (Modern Machinery) Science Journal, December 2014

Bartek Stawiszynski1, Eckart Uhlmann1, Christoph Leyens2, Stefan Heinze2

1TU Berlin, IWF, Institute of Machine Tools and Factory Management, Berlin, Germany
2TU Dresden, IfWW, Institute of Material Science, Dresden, Germany 

e-mail: stawiszynski@iwf.tu-berlin.de

Abstract

Hard processing is defined as the machining of ferrous materials with a hardness of at least 50 HRC. Due to the possibility of the substitution of grinding processes, hard processing has grown in importance in recent years. Fundamental to this was the development of heat and wear resistant cutting materials. The turning of hardened steel is currently possible with cubic boron nitride and ceramic tools, however, hard metals offer a higher versatility and optimization potential. With a choice of different substrate compositions, grain sizes, micro and macro geometry and hard coatings, modern manufacturing technology has a large range of tool combinations. By progressive developments in the field of PVD coating technology it is now possible to deposit hard, dense and smooth layers with sufficient toughness by the application of the HiPIMS (High Power Impulse Magnetron Sputtering) process. In this contribution cemented carbide cutting inserts in combination with varying TiAlN HiPIMS films are studied with regards to their wear behavior in model wear test rigs. The tools are tested not only with regard to their individual wear resistance, the layer adhesion compared with conventional DCMS (Direct Current Magnetron Sputtering) tools is also evaluated afterwards. After evaluating the wear of the HiPIMS layers a promising film-substrate system for the cutting tests is selected. The use and wear behavior of the HiPIMS tools is compared to the behavior of the DCMS coated inserts. The objective is to establish the HiPIMS layer for industrial usage in the hard machining process.

 
Keywords: hard processing, turning, HiPIMS, hard coatings, wear tests
 
Adobe AcrobatDownload full version of the Paper (Adobe Reader Document, 3.2 MB)

___________________________________________________________________________________________________________________________

DEVELOPMENT OF FORCED COOLING USING MIST OF STRONG ALKALINE WATER FOR RESTRAINING THERMAL DEFORMATION ON A MACHINE TOOL

MM (Modern Machinery) Science Journal, December 2014

Ikuo Tanabe

NTU, Deptartment of Mechanical Engineering, Nagaoka, Niigata, Japan

e-mail: tanabe@mech.nagaokaut.ac.jp

Abstract

In this research, forced cooling using mist of strong alkaline water for restraining thermal deformation on a machine tool was developer and evaluated. There are the corrosion resistance of several materials without aluminum, copper and their alloys in alkaline water. Thermal deformations of the bench lathe were effectively restrained by mist of strong alkaline water. When mist of alkaline water was used in the cutting territory, tool temperature during cutting with steel could reduce to 60 %, surface roughness on the work piece at limit of tool life could improve 50 % and the tool life becomed 2.4 times.

 
Keywords: machine tool, thermal deformation, forced cooling,water evaporation, strong alkaline water, mist
 
Adobe AcrobatDownload full version of the Paper (Adobe Reader Document, 4,3 MB)

 

___________________________________________________________________________________________________________________________

HIGH SPEED GEAR HOBBING WITH CEMENTED CARBIDE HOBS

MM (Modern Machinery) Science Journal, December 2014

B. Karpuschewski, M. Beutner, M. Wengler, M. Köchig

Otto von Guericke University Magdeburg
Institute of Manufacturing Technology and Quality Management (IFQ)
Magdeburg, Germany

e-mail: mathias.wengler@ovgu.de

Abstract

As dominating manufacturing process to create external gears, hobbing is of major industrial importance. Hence, a continuous process optimisation to satisfy the demand of the market is necessary. Changing the substrate material is a basic approach in optimization of operation times. Due to acquisition costs and lacking knowledge most companies hesitate to use cemented carbide hobs which endure higher cutting speeds compared to HSS/PM-HSS. Offering experience based knowledge which can be used to revise the cemented carbide application in industry, cutting parameters were varied investigating their influence on the wear behaviour. The impact of high performance cutting parameters within a fly cutting analogy test was examined using different measurement techniques and simulation results.

 
Keywords: gear hobbing, cemented carbide, wear behavior, fly cutting
 
Adobe AcrobatDownload full version of the Paper (Adobe Reader Document, 3.7 MB)
 
 

The following 2 papers were presented at the 3rd International Conference on Design Engineering and Science (ICDES 2014), Pilsen, Czech Republic

 

DESIGN OF PISTON RING SURFACE TREATMENT FOR REDUCING LUBRICATING OIL CONSUMPTION

MM (Modern Machinery) Science Journal, December 2014

Junya Tanaka

Kogakuin University, Department of Mechanical Engineering, Tokyo, Japan

e-mail: junya@cc.kogakuin.ac.jp

Abstract

The reduction of lubricating oil consumption in the internal combustion engines is important for clearing the emission standard and environmental problem, especially the hydrocarbon and particulate matter [Furuhama 1962, Harigaya 2010, Suzuki 2006]. Recently, it is reported
that lubricating oil which exist near the piston ring or piston crown effects strongly for occurrence of pre-ignition in highly supercharged spark ignition engines [Christoph 2010]. This paper describes results of a study on the mechanism of lubricating oil consumption from the top ring with piston motion. The experimental and calculated data show that it is effective the surface treatment of piston ring to reduce lubricating oil consumption. The wetting angle on the piston ring and the viscosity of the lubricant oil are key parameters for lubricating oil consumption from the top ring.
 

Keywords: design, piston ring, surface treatment, lubricating oil,oil consumption
 
Adobe AcrobatDownload full version of the Paper (Adobe Reader Document, 1.8 MB)

___________________________________________________________________________________________________________________________

THE PERFORMANCE OF STIRLING ENGINE OF THE FREE PISTON TYPE ENHANCED WITH SiC CERAMICS HEATER

MM (Modern Machinery) Science Journal, December 2014

Akazawa Teruyuki1, Hirata Koichi2, Hoshino Takeshi3, Fujiwara Kazuhito4

1e-stir Co., Ltd., Maibara City, Shiga, Japan
2National Maritime Research Institute, Tokyo, Japan
3Japan Aerospace Exploration Agency, Tokyo, Japan
4Kumamoto University Graduate School of Science and Technology Kumamoto, Japan

e-mail: akazawa@estir.jp

Abstract

Free piston Stirling engines with integrated linear alternators have the compact size and high conversion efficiency for the sake of the simplicity of mechanical movements. These engines have been developed with the conversion efficiency of 25 %. The material property of ceramics heater is critical in order to achieve such high efficiency. In this paper, the successful design process of the ceramics heater is described. Temperature and stress of the ceramic heater have been calculated by the method of thermo-fluid dynamical analysis and the proper dimensions were decided. Several types of test products have also been designed and manufactured for the evaluation of actual efficiency. Heater efficiency of 63% was estimated from the analysis and the actual test data on free piston engine. It was concluded that the use of ceramics heater in Stirling engine is promising and the high performance of the engine can be realized.

 
Keywords: stirling engine, free piston stirling engine, ceramics heater, silicon carbide, heater efficiency
 
Adobe AcrobatDownload full version of the Paper (Adobe Reader Document, 2.3 MB)