The Effects of Sodium Chloride Solution on Fretting Wear Behavior of Nickel Based Alloy in Partial Slip Regime

2019 ◽  
Vol 62 (2) ◽  
pp. 198-206
Author(s):  
Jie Li ◽  
Yonghao Lu ◽  
Xiaohui Tu ◽  
Wei Li
Author(s):  
Liangliang Sheng ◽  
Xiangtao Deng ◽  
Hao Li ◽  
Yuxuan Ren ◽  
Guoqing Gou ◽  
...  

In this work, an in-situ XPS analysis test combined self-designed high precision fretting wear tester was carried out to study the fretting wear behavior and the resulting tribo-oxidation of thermal-oxidation film on Ti6Al4V titanium alloy under the varied working atmosphere. The fretting-induced tribo-oxidation under the air and vacuum ([Formula: see text] Pa) environment was analyzed and its response on the resulting fretting wear resistance and damage mechanism was discussed. Results show that the working environment plays a significant role in the formation of tribo-oxidation and then determining the fretting wear resistance. Thermal-oxidation film in the vacuum atmosphere shows a better fretting wear resistance than that in the air atmosphere for all fretting regimes, except for partial slip regime (PSR) where there is an equivalent fretting wear resistance. Compared with the substrate Ti6Al4V titanium alloy, the thermal-oxidation film in the vacuum atmosphere performs a good protection for titanium alloy, especially for slip regime (SR), but not applied for air atmosphere.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5778
Author(s):  
Long Xin ◽  
Lanzheng Kang ◽  
Weiwei Bian ◽  
Mengyang Zhang ◽  
Qinglei Jiang ◽  
...  

The effect of displacement amplitude on fretting wear behavior and damage mechanisms of alloy 690 in air and nitrogen atmospheres was investigated in detail. The results showed that in air, the friction coefficient gradually increased with the increase in displacement amplitude which conformed to the universal law. In nitrogen, however, it had the highest point at the displacement amplitude of 60 μm due to very strong adhesion. Whether in air or nitrogen, the wear volume gradually increased with the increase in displacement amplitude. The wear volume in air was larger than that in nitrogen except at 30 μm. At 30 μm, the wear volume in air was slightly smaller. With an increase in displacement amplitude, a transformation of fretting running status between partial slip, mixed stick-slip, and final gross slip occurred along with the change of Ft-D curves from linear, to elliptic, to, finally, parallelogrammical. Correspondingly, the fretting regime changed from a partial slip regime to a mixed regime to a gross slip regime. With the increase in displacement amplitude, the transition from partial slip to gross slip in nitrogen was delayed as compared with in air due to the strong adhesion actuated by low oxygen content in a reducing environment. Whether in air or nitrogen, the competitive relation between fretting-induced fatigue and fretting-induced wear was prominent. The cracking velocity was more rapid than the wear. Fretting-induced fatigue dominated at 30 μm in air but at 30–60 μm in nitrogen. Fretting-induced wear won the competition at 45–90 μm in air but at 75–90 μm in nitrogen.


2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Jianfei Wang ◽  
Weihai Xue ◽  
Siyang Gao ◽  
Bi Wu ◽  
Shu Li ◽  
...  

Abstract Several criteria for fretting wear behavior evaluation have been established since the proposal and establishment of the fretting loop concept. In this article, system deformation and system deformation ratio were defined. In addition, the fretting running conditions were distinguished from the evolution of system deformation with fretting cycles during fretting wear tests under different applied displacements and loads. In the gross slip regime, the system deformation was independent of the applied displacement and increased as the load increased, whereas in the partial slip regime, the system deformation was independent of the load and increased with the applied displacement. Furthermore, a linear relationship between the system deformation and the applied load in gross slip regime was found for the first time. Based on this linear relationship, the system deformation ratio can forecast the running regime with a given load and displacement. For the titanium alloy fretting pairs studied in this article, the fretting wear was found to run in the gross slip regime if the system deformation ratio was smaller than 0.9. Based on these observations, the system deformation ratio exhibited applicability in assisting the mechanical design of equipment suffering from fretting wear.


Author(s):  
Jianfei Wang ◽  
Deli Duan ◽  
Weihai Xue ◽  
Siyang Gao ◽  
Shu Li

Fretting wear between titanium alloy components in aero engine is prevailing in the blade dovetail, the blade crown, and the damping shoulders. In this study, the fretting wear behavior of Ti-6Al-4V alloy was investigated by changing the load and displacement under a high frequency (100 Hz). To simulate the actual working conditions in aero engines, both the ball and flat samples were Ti-6Al-4V alloy. It was found that as the load increased, or as the applied displacement decreased, the fretting regime changed from gross slip regime to partial slip regime. The coefficient of friction/traction at steady stage decreased as load increased. Wear scar morphologies varied with fretting running conditions. In gross slip regime, the central area was higher than the rest region of the wear scar. In the mixed slip regime, large material accumulation could be found at both ends of the reciprocating motion. In partial slip regime, a nearly original fretting sample surface was observed in the central area and wear occurred in the edge area. Furthermore, considering the wear of the paired samples, a method based on the fretting wear scar diameter was proposed to evaluate the fretting running conditions.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Vahid Pourzarghan ◽  
Bahman Fazeli-Nasab

AbstractThe most important inhibitors used in bronze disease are BTA and AMT. While these inhibitors control corrosion, they are toxic and cancerous. In this study, the acacia fruit extract (200 ppm to 1800 ppm) was used to the prevention of corrosion inhibition of bronze alloy in corrosive sodium chloride solution 0.5 M, for 4 weeks consecutively. The Bronze alloy used in this research, was made based on the same percentage as the ancient alloys (Cu-10Sn). IE% was used to obtain the inhibitory efficiency percentage and Rp can be calculated from the resistance of polarization. SEM–EDX was used to evaluate the surfaces of alloy as well as inhibitory. The experiment was conducted in split plot design in time based on the RCD in four replications. ANOVA was performed and comparison of means square using Duncan's multiple range test at one percent probability level. The highest rate of corrosion inhibition (93.5%) was obtained at a concentration of 1800 ppm with an increase in the concentration of the extract, corrosion inhibition also increased, i.e., more bronze was prevented from burning. Also, the highest corrosion inhibitory activity of Acacia extract (79.66) was in the second week and with increasing duration, this effect has decreased. EDX analysis of the control sample matrix showed that the amount of chlorine was 8.47%wt, while in the presence of corrosive sodium chloride solution, after 4 weeks, the amount of chlorine detected was 3.20%wt. According to the morphology (needle and rhombus) of these corrosion products based on the SEM images, it can be said, they are the type of atacamite and paratacamite. They have caused bronze disease in historical bronze works. The green inhibitor of Acacia fruit aqueous extract can play an effective role in inhibiting corrosion of bronze, but at higher concentrations, it became fungal, which can reduce the role of Acacia fruit aqueous extract and even ineffective. To get better performance of green inhibitors, more tests need to be done to improve and optimize.


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