Temperature Dependence of the Friction Coefficient of Grease-Lubricated PTFE Linear Bushings Against Titanium Grade 5 Alloy (Ti6Al4V) and Life Tests Operating at High-Speed

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
I. Valiente-Blanco ◽  
J. L. Perez-Diaz ◽  
J. L. Perez-del-Alamo ◽  
E. Diez-Jimenez
Keyword(s):  
High Speed ◽  
Linear Displacement ◽  
Load Pressure ◽  
Grade 5 ◽  
The Coefficient Of Friction ◽  
Motion Speed ◽  
Life Tests ◽  
Titanium Grade ◽  
Reliable Solution ◽  
Sliding Distance

Abstract Linear bushings are a compact and reliable solution for mechanisms requiring relative linear displacement between moving parts. In this paper, we report the dependence of the coefficient of friction (COF) of polytetrafluoroethylene (PTFE) grease-lubricated bushings against a Ti6Al4 V (grade 5) alloy shaft at high temperatures up to 200 °C, for a motion speed of up to 0.47 m/s and a load pressure of 0.8 MPa. A proportional sensitivity of the COF with temperature is observed due to the change in the viscosity of the grease lubricant. Results of survival tests are also reported demonstrating a total sliding distance of 3200 m without maintenance and a total a total sliding distance of 10,200 m without critical failure.

scholarly journals Dry Sliding Wear Behaviour of Titanium (Grade 5) Alloy by Using Response Surface Methodology

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
S. R. Chauhan ◽  
Kali Dass
Keyword(s):  
Sliding Wear ◽  
Normal Load ◽  
Wear Behaviour ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Sliding Speed ◽  
Grade 5 ◽  
Titanium Grade ◽  
Sliding Distance ◽  
Sliding Wear Behaviour

The dry sliding wear behaviour of titanium (Grade 5) alloy has been investigated in order to highlight the mechanisms responsible for the poor wear resistance under different applied normal load, sliding speed, and sliding distance conditions. Design of experimental technique, that is, response surface methodology (RSM), has been used to accomplish the objective of the experimental study. The experimental plan for three factors at three levels using face-centre central composite design (CCD) has been employed. The results indicated that the specific wear rate increases with an increase in the applied normal load and sliding speed. However, it decreases with an increase in the sliding distance and a decrease in the sliding speed. The worn surfaces of the titanium alloy specimens were analyzed with the help of scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) techniques. The predicted result also shows the close agreement with the experimental results and hence the developed models could be used for prediction of wear behaviour satisfactorily.

scholarly journals Sliding Response of Grade 5 Titanium Alloy at Different Speed and Load Levels

2019 ◽  
Vol 8 (3) ◽  
pp. 4013-4018
Keyword(s):  
Phase I ◽  
Normal Load ◽  
Load Level ◽  
Wear Behaviour ◽  
Grade 5 ◽  
Pin On Disc ◽  
The Coefficient Of Friction ◽  
Speed Level ◽  
Simulated Field ◽  
Titanium Grade

Titanium grade 5 alloy is being very distinct because of light weight and higher strength. These alloys are extensively used in aerospace industries. Response of these Titanium alloys under different load level and speed level during contact is required to be studied. The literature survey indicates inadequate studies on effect of load and speed during relative motion. Experiments have been conducted using Pin-On-Disc test rig in laboratory to simulated field conditions. Two load levels of 1.5kg and 3kg and three speed levels of 500,1000 and 1500rpm were maintained during experiments. Pin surface have been studied under Scanning Electron Micrograph [SEM] for understanding wear behaviour. The coefficient of friction was found to be more sensitive to the speed of sliding. At speed of 1500 rpm, irrespective of normal load, two distinct sliding phases, i.e., phase I and phase II have been observed as sliding progressed. Oxidation of wear debris, at lower speed and phase I of sliding takes place

scholarly journals Is Peripheral Motion Detection Affected by Myopia?

2021 ◽  
Vol 15 ◽  
Author(s):  
Junhan Wei ◽  
Deying Kong ◽  
Xi Yu ◽  
Lili Wei ◽  
Yue Xiong ◽  
...  
Keyword(s):  
Visual Field ◽  
Spatial Frequency ◽  
Motion Detection ◽  
High Speed ◽  
Detection Threshold ◽  
High Spatial Frequency ◽  
Spherical Equivalent ◽  
Detection Thresholds ◽  
Significant Difference ◽  
Motion Speed

PurposeThe current study was to investigate whether myopia affected peripheral motion detection and whether the potential effect interacted with spatial frequency, motion speed, or eccentricity.MethodsSeventeen young adults aged 22–26 years participated in the study. They were six low to medium myopes [spherical equivalent refractions −1.0 to −5.0 D (diopter)], five high myopes (<-5.5 D) and six emmetropes (+0.5 to −0.5 D). All myopes were corrected by self-prepared, habitual soft contact lenses. A four-alternative forced-choice task in which the subject was to determine the location of the phase-shifting Gabor from the four quadrants (superior, inferior, nasal, and temporal) of the visual field, was employed. The experiment was blocked by eccentricity (20° and 27°), spatial frequency (0.6, 1.2, 2.4, and 4.0 cycles per degree (c/d) for 20° eccentricity, and 0.6, 1.2, 2.0, and 3.2 c/d for 27° eccentricity), as well as the motion speed [2 and 6 degree per second (d/s)].ResultsMixed-model analysis of variances showed no significant difference in the thresholds of peripheral motion detection between three refractive groups at either 20° (F[2,14] = 0.145, p = 0.866) or 27° (F[2,14] = 0.475, p = 0.632). At 20°, lower motion detection thresholds were associated with higher myopia (p < 0.05) mostly for low spatial frequency and high-speed targets in the nasal and superior quadrants, and for high spatial frequency and high-speed targets in the temporal quadrant in myopic viewers. Whereas at 27°, no significant correlation was found between the spherical equivalent and the peripheral motion detection threshold under all conditions (all p > 0.1). Spatial frequency, speed, and quadrant of the visual field all showed significant effect on the peripheral motion detection threshold.ConclusionThere was no significant difference between the three refractive groups in peripheral motion detection. However, lower motion detection thresholds were associated with higher myopia, mostly for low spatial frequency targets, at 20° in myopic viewers.

scholarly journals Recovery and Characterization Studies of Post-Production Alloy Waste from the Automotive Industry

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5600
Author(s):  
Sylwester Żelazny ◽  
Witold Żukowski ◽  
Dariusz Bogdał ◽  
Szczepan Bednarz ◽  
Wiktor Kasprzyk ◽  
...  
Keyword(s):  
Automotive Industry ◽  
High Performance ◽  
Inconel 625 ◽  
Muffle Furnace ◽  
High Corrosion Resistance ◽  
Grade 5 ◽  
Washing Process ◽  
Characterization Studies ◽  
Organic Fractions ◽  
Titanium Grade

Superalloys provide high corrosion resistance and are widely used as high-performance materials in aerospace, automotive, chemical, and other industries. Herein, the investigation into the characteristics and properties of alloy waste; Inconel 625, Inconel 718, and Titanium Grade 5, from the automotive industry, was introduced as a result of a recovery in various processes. For this reason, the following procedures were carried as follows; the washing process to remove oil from the swarf was evaluated using several commercial agents and for the process of thermal disposal of processing fluids, a temperature of 900 °C was used in a muffle furnace without air access. The presented studies show that the commercially available series of washing agents did not modify the composition of the surface. However, the high temperatures during the calcination of oil residues are affecting the elemental composition of the alloys. According to the results of the analyses, it is not possible to remove 100% of the oil residues from alloy waste using washing agents based on light organic fractions; however, the effectiveness of this method reaches 99%. In this report, accurate SEM-EDS analyses show changes that occur on the surface after machining and removal of processing fluids. The NMR and GC/MS investigations indicate contaminants as a mixture of aliphatic and cycloaliphatic hydrocarbons with carbon numbers from C8–C30.

scholarly journals Research on the Mechanical Efficiency of High-Speed 2D Piston Pumps

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 853 ◽  
Author(s):  
Yu Huang ◽  
Jian Ruan ◽  
Chenchen Zhang ◽  
Chuan Ding ◽  
Sheng Li
Keyword(s):  
Friction Coefficient ◽  
High Speed ◽  
High Pressures ◽  
Weight Ratio ◽  
Rolling Friction ◽  
Mechanical Efficiency ◽  
Load Pressure ◽  
Axial Piston Pumps ◽  
Series Of Experiments ◽  
Rolling Friction Coefficient

Since many studies on axial piston pumps aim at enhancing their high power-weight ratio, many researchers have focused on the generated mechanical losses by the three friction pairs in such pumps and attempted to diminish them through abundant and new structural designs of the pump’s components. In this paper, a high-speed 2D piston pump is introduced and its architecture is specifically described. Afterward, a mathematical model is established to study the pump’s mechanical efficiency, including the mechanical losses caused by the viscosity and stirring oil. Additionally, in this study the influences of the rotational speed, the different load pressures, and the rolling friction coefficient between the cone roller and the guiding rail are considered and discussed. By building a test rig, a series of experiments were carried out to prove that the mechanical efficiency was accurately predicted by this model at low load pressures. However, there was an increasing difference between the test results and the analytical outcomes at high pressures. Nevertheless, it is still reasonable to conclude that the rolling friction coefficient changes as the load pressure increases, which leads to a major decrease in the mechanical efficiency in experiments.

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