Study of Ti-1023 milling with toroidal tool

Proceedings of the Institution of Mechanical Engineers, Part B:

Barelli²,

Dessein

et al. 2017

Self Cite

For a number of years, the rise in the number of titanium alloy grades and therefore of microstructures has hampered the productivity of titanium parts. In order to understand the phenomena involved, this study presents a comparison of the chip formations between two microstructures obtained from the same alloy. The first part presents the two alloys, their microstructures and their methods of production. The chip formation of each material is then presented and shows two completely different processes. The first process is classical, for which shear mechanisms appear to be cyclical. Conversely, the second process depends on the orientation of the microstructure when the shear occurs. For a better understanding of the phenomena, the effect of cutting speed and feed is also discussed. Finally, in the last section, chip formations for the two microstructures are summarized and perspectives are presented.

Section: Cutting Conditions Effectsupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Comparison of the chip formations during turning of Ti64 β and Ti64 α+β

Proceedings of the Institution of Mechanical Engineers, Part B:

Barelli²,

Dessein

et al. 2017

Self Cite

“…One of them concerns the Ti64 a þ b carried out by Komanduri and Von Turkovich [1] and Vyas and Shaw [2]. Since then, different studies have been performed on the same alloy by Barry et al [3] and Nouari and Makich [4] and on the Ti1023 (b structure) by Wagner and Duc [5], the Ti5553 (a near b metastable) [6][7][8], and the Ti17 [9]. However, the majority of these papers concern the machining of bimodal structures where a nodules occur in the b matrix.…”

Section: Introductionmentioning

confidence: 99%

Thermal and Microstructure Study of the Chip Formation During Turning of Ti64 β Lamellar Titanium Structure

Journal of Manufacturing Science and Engineering

Barelli²,

Dessein

et al. 2017

Self Cite

In recent years, many titanium alloys have emerged, each of them associated with a range of different heat treatments. Thus, several microstructures have been studied to varying degrees. For example, the Ti64 titanium alloy, mostly known for its α + β structure, can display a different state: the structure, inducing nonstandard mechanical behavior. This work presents chip formation in this specific microstructure where a strong heterogeneity is observed and where the shear band formation is a function of the relationship between the shear direction and the microstructure orientation. From these reasons, major differences are found in the chip morphology, within the same cutting condition, in comparison to the bimodal structure where a single chip morphology is obtained for each cutting condition. A section of this paper is devoted to the presentation of the β microstructure where different configurations can be seen within the same chip. Next, the influence of cutting conditions on the chip formation is studied. To highlight the specific chip formation process, a temperature model has been developed and combined with cutting force analysis to understand clearly the specificity of the chip formation for this structure. Finally, the discussion explains the different chip formation scenarios according to the workpiece microstructure to be cut.

“…Tool wears in titanium alloys have been studied for a longtime. 1,2 A common solution to avoid tool breakage is to strengthen the edge by edge preparations such as a chamfer. Thus, it remains to find optimal tool geometries and cutting conditions in order to slow down or prevent diffusion wear mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Orthogonal cutting of TA6V alloys with chamfered tools: Analysis of tool–chip contact lengths

Barelli

Proceedings of the Institution of Mechanical Engineers, Part B:

Laheurte

et al. 2016

Self Cite

In aerospace industry, the materials constituting aircraft evolved considerably in recent decades. The choice of composite materials (carbon fiber-reinforced plastic or multi-material) reduces the weight of structures, but for critical parts that support important forces or temperature, the indicated materials are alloys based on nickel or titanium. Consumption of titanium for the aerospace industry is growing rapidly, and the new generations of aircraft show an increase in the percentage of titanium. The TA6V is mostly used for structural parts, especially for engine pylon. Due to its low thermal properties, it shows a poor machinability, leading tools to undergo severe wears. The aim of this work is to understand the relation between cutting conditions and chamfered tool geometries on chip formation and tool wear. Based on a model dedicated to the understanding of cutting process with chamfered tool and on experimental tests, this work will show the influence of feed, cutting speed, chamfer length and rake angle on tool-chip contact lengths. It will also show the influence of these parameters on the variability of these contacts within a same geometry or cutting condition. This will lead to another interpretation of tool wears and pressures on the rake face.