A Comparison of Fluids Used to Superabrasively Machine a Titanium Alloy

1991 ◽  
Author(s):  
James D. Campbell
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Specific Energy ◽  
Compressive Residual Stress ◽  
Water Soluble ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Fluid Type ◽  
Power Flux ◽  
Screening Design

The objective of this paper was to compare the creep feed superabrasive machining of an alpha-beta structural titanium alloy, using a water-soluble and a straight oil grinding fluid, in terms of residual stress, specific energy, power flux and microstructure. The statistical effect of process variables on these criteria was investigated using a Taguchi screening design of experiment. Grinding wheel peripheral velocity, abrasive size and fluid type were the most important factors contributing to compressive residual stress. After the depth of cut, fluid type contributed the most variation to specific energy and power flux. Both fluids produced testpieces that were microstructurally sound, and were essentially stress free or had favorable compressive residual stress.

Effect of the Type of Grinding Wheel on the Surface Characteristics of a Titanium Alloy with Internal Coolant Supply

2019 ◽  
Vol 825 ◽  
pp. 92-98
Author(s):  
Nakatsuka Nagatoshi ◽  
Sumito Toyokawa ◽  
Atsushi Kusakabe ◽  
Shinya Nakatsukasa ◽  
Hiroyuki Sasahara
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Silicon Carbide ◽  
Titanium Alloy ◽  
Aluminum Oxide ◽  
Compressive Residual Stress ◽  
Surface Characteristics ◽  
Grinding Wheel

The objective of this paper is to clarify the effect of grinding surface characteristics in the grinding of a titanium alloy with a coolant supply from the inner side of the grinding wheel. In this paper, we selected a white aluminum oxide (WA) vitrified bonded grinding wheel and a green silicon carbide (GC) vitrified bonded grinding wheel, and compared their grinding characteristics. As a result, in the case of the GC vitrified bonded grinding wheel, the surface roughness decreased by about 54% and the compressive residual stress increased by about 128%.

Effect of Coolant Supplied through Grinding Wheel on Residual Stress of Grinding Surface

2014 ◽  
Vol 1017 ◽  
pp. 33-37 ◽  
Author(s):  
Nagatoshi Nakatsuka ◽  
Yudai Hirai ◽  
Atsushi Kusakabe ◽  
Yasuhiro Yao ◽  
Hiroyuki Sasahara
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Temperature ◽  
Internal Grinding ◽  
Grinding Fluid ◽  
Fluid Supply ◽  
Infrared Thermograph

We explored the effect of supplying coolant from the inner side of a grinding wheel on the residual stress caused by grinding. Effect of depth of cut on grinding temperature and residual stress was also studied. Results clarified that grinding with an internal coolant supply induced a larger compressive residual stress compared to a conventional external grinding fluid supply when depth of cut was large. In addition, grinding temperature in the internal grinding fluid supply was lower than in the external grinding fluid supply, as measured by infrared thermograph camera. Findings suggested that large compressive residual stress was obtained in the case of the coolant supplied from the inner side of the grinding wheel because temperature was lower than external coolant supply.

Peripheral milling-induced residual stress and its effect on tensile–tensile fatigue life of aeronautic titanium alloy Ti–6Al–4V

2019 ◽  
Vol 123 (1260) ◽  
pp. 212-229 ◽  
Author(s):  
Dong Yang ◽  
Xiao Xiao ◽  
Yulei Liu ◽  
Jing Sun
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Fatigue Life ◽  
Surface Energy ◽  
Compressive Residual Stress ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Stress Profile ◽  
Peripheral Milling ◽  
Residual Stress Profile

ABSTRACTThe special application environment puts forward the higher requirement of reliability of parts made from titanium alloy Ti–6Al–4V, which is closely related to the machining-induced residual stress. For the fact of the non-linear distribution of residual stress beneath the machined surface, distribution of peripheral milling-induced residual stress and its effect on fatigue performance of titanium alloy Ti–6Al–4V are still confusing. In the present study, residual stress profile induced by peripheral milling of Ti–6Al–4V is first studied. And then, energy criteria are proposed to characterise the whole state of the residual stress field. Finally, the effects of residual stress profile and surface energy on tensile–tensile fatigue performance of titanium alloy Ti–6Al–4V are discussed. The conclusions were drawn that the variation trend of surface residual stress (σr,Sur), maximum compressive residual stress (σC,ax), location (hr0) and response depth (hry) of residual stress profile with cutting parameters showed a similar pattern for both measure directions those parallel (σ1) and perpendicular (σ3) to the cutting direction. Cutting speed and feed rate have a main effect on surface residual stress, and the depth of cut has little effect on all the four key factors of residual stress profile. With the increase of cutting speed and feed rate, machining-induced surface energy tends to become larger. But increasing the depth of cut caused the strain energy stored in unit time to decrease. Furthermore, the effect of depth of cut on surface energy was weakened when the value of cutting depth becomes larger. Both the surface compressive residual stress and the maximum compressive residual stress are beneficial for prolonging the fatigue life, while large value of machining-induced surface energy leads to a decrease of fatigue life. Analysis of variance result shows that maximum residual compressive stress has a greater impact on fatigue life than other residual stress factors.

Effect of residual stress of grinding of titanium alloy machined with coolant supply from inner side of grinding wheel

2017 ◽  
Vol 2017 (0) ◽  
pp. S1310204
Author(s):  
Sumito TOYOKAWA ◽  
Nagatoshi NAKATSUKA ◽  
Atsushi KUSAKABE ◽  
Hiroyuki SASAHARA
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Grinding Wheel

scholarly journals Introduction of Compressive Residual Stress by Means of Cavitation Peening into a Titanium Alloy Rod Used for Spinal Implants

2013 ◽  
Vol 04 (07) ◽  
pp. 23-28 ◽  
Author(s):  
Osamu Takakuwa ◽  
Amrinder S. Gill ◽  
Gokul Ramakrishnan ◽  
Seetha R. Mannava ◽  
Vijay K. Vasudevan ◽  
...  
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Compressive Residual Stress ◽  
Spinal Implants

Effect of ultrasonic longitudinal–torsional composite milling of the residual stress on the surface of titanium alloy

2019 ◽  
Vol 234 (8) ◽  
pp. 1598-1608
Author(s):  
Jinglin Tong ◽  
Junshuai Zhao ◽  
Peng Chen ◽  
Zhiming Zhang ◽  
Bo Zhao
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Compressive Stress ◽  
Tool Path ◽  
Orthogonal Experiment ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Vibration Direction ◽  
Workpiece Surface

The present study envisages the study of the residual stress characteristics of titanium alloy surface, based on the ultrasonic longitudinal–torsional composite milling process. Initially, the tool path analysis of common milling and ultrasonic longitudinal–torsional composite milling was performed. When compared with the common milling, it was found that the tool–chip cycle separation phenomenon occurred in the torsional vibration direction in the ultrasonic milling tool path. Subsequently, an ultrasonic longitudinal–torsional composite milling experimental platform was built and the effects of the ultrasonic amplitude (A), cutting speed ( vf), axial depth of cut ( ap), and feed per tooth ( fz) on the residual stress of titanium alloy were studied using an orthogonal experiment. The results indicated that the residual stress in ultrasonic longitudinal–torsional composite milling comprised a combination of the “plastic bulge effect” caused by cutting force–cutting heat and the “extrusion effect” of the tool flank on the workpiece. The “extrusion effect” was dominant and presented a compressive stress on the machined surface. The ultrasonic amplitude (A) showed the most significant influence on the residual stress. With an increase of the amplitude, the extrusion and collision effect of the tool on the workpiece surface became more obvious, along with a stronger “extrusion effect” between the tool and the workpiece surface. Experimental results provide a good processing method for the difficult-to-machine materials such as titanium alloy, and offers an effective method for obtaining large surface residual compressive stress.

Paper 40: Measurement and Control of the Residual Stress Produced by Grinding Operations

1967 ◽  
Vol 182 (11) ◽  
pp. 205-210 ◽  
Author(s):  
J. Loxham ◽  
J. Purcell
Keyword(s):  
Residual Stress ◽  
Graphical Form ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Full Explanation ◽  
The Individual ◽  
Grinding Operations ◽  
And Control ◽  
Measurement And Control ◽  
Made In

The grinding process is surveyed and a technique is described which enables the efficiency of the grinding wheel, coolant, and machine tool system to be determined. The analysis is made in terms of the maximum possible depth of cut that can be taken by the individual grits of the grinding wheel and the volume of material removed from the workpiece at this loading per unit volume of grinding wheel lost. Suggestions are made for the practical application of the technique to minimize the residual stress which is produced by the grinding operation. The results which have been achieved are shown in graphical form, and suggestions are made for the full explanation of the technique.

Grinding Titanium Alloy with Brazed Monolayer CBN Wheels

2007 ◽  
Vol 359-360 ◽  
pp. 33-37 ◽  
Author(s):  
Chang Yong Yang ◽  
Jiu Hua Xu ◽  
Wen Feng Ding ◽  
Sheng Ting Tong
Keyword(s):  
Titanium Alloy ◽  
Surface Layer ◽  
Process Parameters ◽  
Specific Energy ◽  
Grinding Wheel ◽  
Grinding Temperature ◽  
Grinding Wheels ◽  
Excellent Performance ◽  
Design Requirements ◽  
Cbn Grinding Wheel

This paper deals with an investigation of the grindability of Titanium alloy Ti–6Al–4V with brazed monolayer CBN grinding wheels, and systematically studies the effect of process parameters on specific energy and grinding temperature. In the investigation, a groove is machined with a brazed monolayer CBN grinding wheel, and the dimension accuracy of groove has been proved to meet the design requirements. There is no microcrack in surface layer of the groove, and the depth of work-hardening is less than 40 μm, which indicates that the grinding affected zone is small. The results show that brazed monolayer CBN grinding wheels have excellent performance during grinding titanium alloy.

scholarly journals Effect of Residual Stress on S–N Curves and Fracture Morphology of Ti6Al4V Titanium Alloy after Laser Shock Peening without Protective Coating

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3799 ◽  
Author(s):  
Xinlei Pan ◽  
Xiang Li ◽  
Liucheng Zhou ◽  
Xiaotai Feng ◽  
Sihai Luo ◽  
...  
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Fatigue Life ◽  
Compressive Residual Stress ◽  
Fracture Morphology ◽  
High Amplitude ◽  
Laser Shock ◽  
Ti6al4v Titanium Alloy ◽  
Before And After ◽  
Shock Peening

In this paper, the effect of residual stress on the stress–life (S–N) curve and fracture morphology characteristics of Ti6Al4V titanium alloy after laser shock peening (LSP) without protective coating was experimentally investigated. The fatigue test and residual stress measurement were conducted on specimens before and after the LSP process. It was shown that LSP produced a high-amplitude compressive residual stress field on the surface of the specimen. After the LSP process, the fatigue life limit was increased by 16%, and the S–N curve shifted upward. Then, based on the theory of mean stress, the mechanism whereby the compressive residual stress improves the fatigue life of Ti6Al4V titanium alloy was analyzed. It indicated the improvement in fatigue life was because of the high-amplitude compressive residual stress on the surface and in depth induced by LSP to reduce the tensile stress produced by external loading. In addition, the scanning electron microscope (SEM) pattern of fatigue fracture demonstrated distinct differences in the fracture morphology before and after LSP. After LSP, the crack initiation sites of the samples moved to the subsurface where it was difficult for fatigue cracks initiating here. Moreover, after the LSP process, there were high density of fatigue striations and many secondary cracks on the fracture of the treated specimen.

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