Wyniki wyszukiwania - Biblioteka Nauki

1

Variation cutting speed on the five axis milling

100%

Boujelbene M. , Moisan A. , Bouzid W. , Torbaty S.

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tom Vol. 21, nr 2

7-14

EN

Purpose: The aim of this research is to make a study of the effective cutting speed variation in milling with a ball end tool. Then an experimental study of the effect of finishing strategies on surface texture, roughness is described. The material of a specific HB 300 pre-hardened mould steel Super Plast (SP 300). Design/methodology/approach: The methodology has consisted to determine cutting speed of each mode of tilt tool in five axes machining, and of proving a series of configurations and parameters combinations: cutting speed Vc, feed rate Vf, and tilt tool in multi-axis milling. Findings: This paper has investigated the effect of the tool orientation on the variation effective cutting speed, on the surface texture, while multi-axis milling. Experimental results have shown that disadvantages of three axes machining results from the existence of very low cutting speeds, even null when the tool axis is normal to the machined surface. This mode of machining generates a bad surface quality. Surfaces have a poor topography and important anisotropy. A suitable slope of the cutting tool by the means of the fifth machine tool axis, improves considerably work piece machined surface quality; Good micro-geometrical surface topography and lower surface roughness. Research limitations/implications: A possible future work would be the development of a general the phenomenal of the residual stress of the cutting on the five axis machining. The behavior of the residual stress studies are planed in the future. Practical implications: The relationship found between the effective cutting speed and surface texture work piece has an important practical implication since it allows selecting the best cutting condition combination from the points of view both the security and the economy for the established requirements in each case. Results are of great importance in for aerospace and automotive industry. Originality/value: The paper is original since the bibliographical review has allowed testing that, although works about these themes exist, none approaches the problem like it has been made in work.

2

Study of the milling strategy on the tool life and the surface quality for knee prostheses

100%

Boujelbene M. , Abellard P. , Bayraktar E. , Torbaty S.

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tom Vol. 31, nr 2

610-615

EN

Purpose: The aim of this research is to make a study about the influence of the tool trajectory's generation on its tool life and the improvement of the surface quality in multi-axis milling at high speed machining of the knee prostheses. The material used for this study is the titanium alloy Ti-6Al-4V ELI (TA6V ELI) for implant. Design/methodology/approach: The methodology has consisted on proving a serie of parameters combinations with various machining configurations and various programs of the tool trajectory's generation in three and five axes (the axis of the tool is maintained normal on the machined surface by rotation around Y axis; the axis of the tool is maintained according to axis Z; the axis of the tool is tilted around the Y axis). And determined the influence of the machining strategy over of the tool life. Findings: The knee prostheses are constructed with important mechanical resistance materials with complex form, which require high performance cutting tools and high cost. The good generation's trajectory of the cutting tool in multi-axes milling permits to minimize flank wear. High speed Machining offers a considerable profit in the capacity of surface quality, duration of the machining and polishing operations and consequently in improvement productivity. But the choice of the cutting speed must be recommended by the couple tool-materials. Research limitations/implications: A possible future work would be the development of a general the phenomenal of the residual stress of various machining configurations and various programs of the tool trajectory's generation and the knee protheses life. The behaviour of the residual stress studies are planed in the future. Practical implications: The relationship found between the milling strategy on the tool life and surface quality work piece has an important practical implication since it allows selecting the best cutting condition for knee prostheses. Results are of great importance in the quality of articulation surface so the cartilage in medicine industry. Originality/value: The paper is original since the bibliographical review has allowed testing that, although works about these themes exist, none approaches the problem like it has been made in this work. This paper could be an interesting source of information for engineers and researchers who work with machining knee prostheses.

3

Influence of workpiece inclination angle on the surface roughness in ball end milling of the titanium alloy Ti-6Al-4V

88%

Daymi A. , Boujelbene M. , Linares J. M. , Bayraktar E. , Ben Amara A.

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2009

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tom Vol. 35, nr 1

79-86

EN

Purpose: The aim of this work is to provide an in-depth understanding of the surface texture produced by various workpiece inclination angles using high speed finish ball end-milling of the titanium alloy Ti-6Al-4V. Design/methodology/approach: This paper presents an approach to develop a mathematical model of surface roughness in end-milling by the experimental design methodology. Machining variables such as cutting speed, feed and radial depth of cut, which are easily controllable, are considered in building the model. The influence of the workpiece inclination angle on the surface roughness of the machined workpiece was also investigated. Findings: According to the mathematical model, an increase in either the feed or the radial depth of cut increases the surface roughness, whilst an increase in cutting speed decreases it. The radial depth of cut ae is the most significant parameter in the model. Results analysis of the 2D/3D surface roughness parameters of the machined parts shows the improvement of the surface roughness quality when it is machined with a workpiece inclination angle of 25°. Research limitations/implications: As perspectives of this work, we can study the influence of the different machining strategies on the surface integrity of this titanium alloy, including the study of the residual stress. Practical implications: We propose to study the improvement of the surface quality of the orthopedic prostheses, which is an influencing parameter in their lifetime, by implementing the high speed cutting technique. The mathematical model of the surface roughness is a very important result of this work. In fact, it allows selecting the best cutting conditions to obtain a better workpiece surface quality. Originality/value: In this work, three dimensional surface roughness parameters were studied: the 3D surface topographies were obtained using a 3D measurement station and the mathematical model of Sa. The arithmetic mean deviation of the surface was established in order to minimize the experimental works and to have an idea about the surface roughness evolution as a function of cutting parameters.