Surface Integrity Analysis of Ti6Al4V After Semi-finishing Turning Under Different Low-Temperature Cooling Strategies

Sartori, Stefano; Pezzato, Luca; Dabalà, Manuele; Enrici, Tommaso Maurizi; Mertens, Anne; Ghiotti, Andrea; Bruschi, Stefania

doi:10.1007/s11665-018-3598-x

Cited by 32 publications

(9 citation statements)

References 28 publications

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“…Although the results differed because of the end mill treatment conditions, the major reason behind such a rise in microhardness lies in the fact that the low temperatures induce strain hardening and grain refinement in the surface being machined and substantially lower down the thermal softening and high temperature in the milling zone. 33 Hence, in Figure 3(c), cryo-lubri-coolant-milled surfaces with the untreated end mill were observed with the highest microhardness, followed by hybrid and wet-lubri-coolant-milled surfaces. However, as explained above in the case of the cryo-treated end mill (Figure 3(d)), the end mill fails to perform satisfactorily in the low temperature lubri-coolant-milling conditions due to the development of micro cracks at high cutting speed and increase in the chances of tool breakage at the high feed rate and depth of cut.…”

Section: Resultsmentioning

confidence: 89%

Performance Study of Cryo-Treated End Mill Via Wet, Cryogenic, and Hybrid Lubri-Coolant-Milling Induced Surface Integrity of Biocompatible Mg Alloy AZ91D

Davis

Singh

2021

Proceedings of the Institution of Mechanical Engineers, Part C:

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The excellent biodegradability of the magnesium (Mg) alloys is gradually proving them as the potential substitutes to several biomedical implants such as chemotherapy ports or screws, which are required to be removed via secondary surgeries after a specific period of time. However, an early degradation of these alloys even before the complete healing of the damaged tissue, when exposed to the physiological atmosphere, has been limiting their full-fledged application. Some latest research articles suggest that such challenges can be effectively overcome by improving the surface integrity of Mg alloys using the sustainable manufacturing techniques, such as cryogenic machining. Recent literatures also report the outperformance of the cryogenically treated (cryo-treated) cutting tools for achieving an enhanced surface integrity. In this relation, the present research attempts to improve the surface integrity of one of the most commonly used biocompatible alloys of magnesium, known as AZ91D. For this reason, a TiAlN coated-cemented carbide end mill was used in an untreated and cryo-treated state amid wet, cryogenic, and hybrid-lubri-coolant-milling conditions. The milling and FESEM (field emission scanning electron microscopy) results showed a considerable improvement in the surface integrity in terms of an augmented surface roughness and microhardness at 56.52 m/min cutting speed with the cryo-treated end mill during hybrid-lubri-coolant-milling. At the high cutting speed hybrid-lubri-coolant-milling, the cryo-treated end mill attained 35.71% and 48.07% better surface finish than that of cryo and wet-lubri-coolant-milling, respectively. Although, the highest surface microhardness was achieved by the cryo-treated end mill amid cryo-lubri-coolant-milling, due to the poorest surface quality observed in terms of the maximum number of machining-induced cracks, the hybrid-lubri-coolant-milled surface was preferred over the cryo and wet-lubri-coolant-milled surfaces. Further, the FESEM and EDS (energy-dispersive X-ray spectroscopy) analyses confirmed the oxide layer produced by the cryo-treated end mill amid hybrid-lubri-coolant-milling, to be the thinnest (12.16 µm) and most uniform passivation layer.

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Section: Resultsmentioning

confidence: 89%

Performance Study of Cryo-Treated End Mill Via Wet, Cryogenic, and Hybrid Lubri-Coolant-Milling Induced Surface Integrity of Biocompatible Mg Alloy AZ91D

Davis

Singh

2021

Proceedings of the Institution of Mechanical Engineers, Part C:

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“…On the contrary, the gaseous N2 cooled at -100°C÷150°C allow reducing the heat generated during the cutting process, thus limiting the crater wear, but without modifying the initial material characteristics and thus limiting also the flank wear. Therefore, use of cooled gaseous N2 represents the best strategy for semi finishing turning of the Ti6Al4V, since it minimizes the surface defects and surface microstructural alterations ensuring, at the same time, a significant compressive state of residual stresses that can improve the fatigue resistance of the final product [18][19], (Fig. 3).…”

Section: High Performance Cooling Techniques 21 Cryogenic Machiningmentioning

confidence: 99%

“…3. Tool flank wear and thickness of the machining-altered layer as a function of the adopted cooling strategies during semi finishing turning of the Ti6Al4V [18][19] Also, during rough turning of Ti6Al4V application of metalworking fluid (MWFwater and polyhydric alcohols) cooled down to -30°C, resulted in lower tool wear and favorable chips compared with emulsion, CO2, LN2, and dry machining [20]. Fig.…”

Section: High Performance Cooling Techniques 21 Cryogenic Machiningmentioning

confidence: 99%

Review of new developments in machining of aerospace materials

Jemielniak¹

2021

Journal of Machine Engineering

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The paper presents an update of the recent literature on advances in machining of difficult to machine materials such as nickel and titanium-based alloys, and composites used in aeroengine and aerostructure applications. The review covers the following issues: advances in high-performance cooling techniques as cryogenic machining, minimum quantity lubrication, the combination of MQL and cryogenic cooling, and high-pressure lubricoolant supply and hybrid cutting processesvibration assisted machining (both low and high frequency), laser, plasma and EDM assisted machining. Examples of applications in industrial processes are also given.

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“…The surface machining technology of titanium alloy has been studied extensively. Sartori studied the integrity of the semi-finished surface of Ti6Al4V titanium alloy under different cryogenic cooling techniques, and the results showed that the machined surface had no defects and had the best integrity when N 2 cooling was used at −150 °C [ 7 ]. Lin treated the surface of titanium alloy with sandblasting and grinding methods and carried out 3-point bending test.…”

Section: Introductionmentioning

confidence: 99%

Study on Surface Integrity and Fatigue Properties of TC4 Titanium Alloy by Surface Ultrasonic Rolling

et al. 2023

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In this paper, the influence of a surface ultrasonic rolling process on the surface integrity of TC4 titanium alloy and its influence on the fatigue properties were studied. By comparing and analyzing the surface roughness, microhardness, residual stress, microstructure, and fatigue fracture, the surface strengthening and modification mechanism of TC4 titanium alloy is discussed. The results show that the surface roughness of titanium alloy is observably decreased after the suitable surface ultrasonic rolling process, and the maximum Ra value can be reduced to 0.052 μm. The axial residual stress on the specimen surface can be increased to −685 MPa. The hardening rate of the surface hardness of the sample was 35%. The residual compressive stress and hardness of the sample surface increased with the increase of static pressure. However, the increase of feed rate and rational speed was less. After surface ultrasonic rolling, the sample surface exhibited obvious grain refinement, the number of high-angle boundaries increased to include the formation of nano-equiaxed grains. The fatigue strength increased by 52% from 280 MPa to 425 MPa. Under 450 MPa, the fatigue life of samples with SUR 2 was the highest, at about 7.7 times that of the original samples. The surface integrity of titanium alloy samples after surface ultrasonic rolling treatment is greatly improved, which is the reason for the significant increase in fatigue life of the samples.

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Surface Integrity Analysis of Ti6Al4V After Semi-finishing Turning Under Different Low-Temperature Cooling Strategies

Cited by 32 publications

References 28 publications

Performance Study of Cryo-Treated End Mill Via Wet, Cryogenic, and Hybrid Lubri-Coolant-Milling Induced Surface Integrity of Biocompatible Mg Alloy AZ91D

Performance Study of Cryo-Treated End Mill Via Wet, Cryogenic, and Hybrid Lubri-Coolant-Milling Induced Surface Integrity of Biocompatible Mg Alloy AZ91D

Review of new developments in machining of aerospace materials

Study on Surface Integrity and Fatigue Properties of TC4 Titanium Alloy by Surface Ultrasonic Rolling

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