scholarly journals Detecting Safety Zone Drill Process Parameters for Uncoated HSS Twist Drill in Machining GFRP Composites by Integrating Wear Rate and Wear Transition Mapping

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Sathish Rao Udupi ◽  
Lewlyn Lester Raj Rodrigues

The previous research investigations informed that the tool wear of any machining operation could be minimized by controlling the machining factors such as speed, feed, geometry, and type of cutting tool. Hence the present research paper aims at controlling the process parameters to minimize the drill tool wear, during the machining of Glass Fiber Reinforced Polymer (GFRP) composites. Experiments were carried out to find the tool wear rate and a wear mechanism map of uncoated High Speed Steel (HSS) drill of 10 mm diameter was developed for the drilling of GFRP composite laminates. The surface micrograph images on the drill land surface displayed dominant wear mechanisms induced on HSS drill during machining of GFRP and they were found to be adhesive wear, adhesive and abrasive wear, abrasive wear, and diffusion and fatigue wear. A “safety wear zone” was identified on the wear mechanism map, where the minimum tool wear of the HSS drill occurs. From the safety zone boundaries, it was inferred that the drill spindle speed should be set between 1200 and 1590 rpm and feed rate must be set within a range of 0.10–0.16 mm/rev for GFRP work and HSS tool combination to enhance the service life of 10 mm HSS drills and to minimize the tool wear.

Author(s):  
Shao Lifan ◽  
Ge Yuan ◽  
Kong Dejun

In order to improve the friction and wear properties of Cu10Al–MoS2 coating, the addition of CeO2 is one of the present research hot spots. In this work, Cu10Al–MoS2 coatings with different CeO2 mass fractions were successfully fabricated on Q235 steel using a laser cladding. The microstructure and phase compositions of obtained coatings were analyzed using an ultra-depth of field microscope and X-ray diffraction, respectively. The friction-wear test was carried out under oil lubrication using a ball-on-disk wear tester, and the effects of CeO2 mass fraction on the microstructure, hardness, and friction-wear properties were studied, and the wear mechanism was also discussed. The results show that the laser cladded Cu10Al–MoS2 coatings with the different CeO2 mass fractions were mainly composed of Cu9Al4, Cu, AlFe3, Ni, MoS2, and CeO2 phases. The Vickers-hardness (HV) of Cu10Al–8MoS2–3CeO2, Cu10Al–8MoS2–6CeO2, and Cu10Al–8MoS2–9CeO2 coatings was 418, 445, and 457 HV0.3, respectively, which indicates an increase in hardness with the increase of CeO2 mass fraction. The average coefficients of friction (COF) and wear rates decrease with the increase of CeO2 mass fraction, presenting the outstanding friction reduction and wear resistance performances. The wear mechanism of Cu10Al–MoS2 coatings is changed from abrasive wear with slight fatigue wear to abrasive wear with the increase of CeO2 mass fraction.


2019 ◽  
Vol 11 (1) ◽  
pp. 56-61
Author(s):  
Wei Yuan ◽  
Shengkai Mei ◽  
Song Li ◽  
Zhiwen Wang ◽  
Jie Yu ◽  
...  

Background: Grooves may inevitably occur on the surface of the friction pair caused by severe wear or residual stress, which will play an important role on the reliability of machine parts during operation. Objective: The effect of the micro-grooves perpendicular to sliding direction on the wear performance of the friction pairs should be studied. Method: Micro-grooves can be machined on discs of friction pairs using electrical discharge machining. On-line visual ferrograph method was used to monitor the wear process to research the wear rate changing characteristic. Profilemeter and metallurgical microscope were used to observe the wear scars. Results: Comparing to the non-groove test, i) in one-groove test, wear volume and rate were approximate the same, and the wear scar was smooth, ii) when the grooves more than 4, the test running-in stage will be obviously prolonged, particularly for the test with 8 grooves on the disc, the duration of running-in stage is 4 times than that without grooves on specimen, and the wear rate and volume increase significantly, and then decrease with fluctuation, iii) the abrasive wear can be avoid with the debris stagnating in the groove, however, fatigue wear will significantly emerge. Conclusion: Abrasive wear can be avoided and smooth running-in surfaces can be obtained with proper amount of initial radial micro-grooves.


In this experimental work , we investigated optimization of process parameters in EDM using Taguchi method by taking Low carbon steel as work piece. Process parameters chosen were Pulse on-time (Ton), Flushing pressure(P) and Pulse Current(IP) . Here we have chosen L9 orthogonal array to study the effect of main factors and interaction between factors on the response variable i.e. Surface Roughness (SR), Material removal Rate (MRR) and Tool Wear Rate (TWR). The contribution of the main factors and interaction were determine here. The MR), TWR and surface integrity are some of the important performance attributes of EDM process. The objective of EDM is to get high MRR along with achieving reasonably good surface quality of machined component with reduced tool wear rate for Low carbon steel material.


Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4678
Author(s):  
Jiapeng Liu ◽  
Yingqi Li ◽  
Yinhua Zhang ◽  
Yue Hu ◽  
Lubing Shi ◽  
...  

This study aims to deeply understand the effect of contact stress and slip ratio on wear performances of bainitic rail steels. The results showed that the wear loss increased as the contact stress and slip ratio increased. Based on the surface damage morphology and microstructural analyses, it revealed that the rolling contact fatigue wear mechanism played a significant role under the low slip ratio, but the dominant wear mechanism transferred to the abrasive wear at the high slip ratio. Meanwhile, the bainitic steel specifically presented worse wear resistance under the abrasive wear mode. Compared with the influence of a slip ratio, the increase in contact stress led to severer plastic flows and contributed to the propagation of cracks. In addition, the contact stress and slip ratio had the opposite effect on the friction coefficient, that is, the friction coefficient of bainitic steels behaved the inverse proportion with the contact stress, but positive proportion with the slip ratio. At last, the increase in slip ratio had more significant effect on the reduction of retained austenite (RA) than the enlargement of contact stress due to the fact that the RA would probably be removed before the martensitic transformation occurred under the abrasive wear mechanism.


Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1561
Author(s):  
Xin Guo ◽  
Xi Jin ◽  
Xiaohui Shi ◽  
Huijun Yang ◽  
Min Zhang ◽  
...  

The tribological behavior of hot-rolled and boronized Fe40Mn20Cr20Ni20 high-entropy alloys (HEAs) sliding against a Si3N4 ball was investigated in the air, deionized water and seawater. The results showed that the hot-rolled Fe40Mn20Cr20Ni20 HEA was composed of an FCC (face-centered cubic) phase. In addition, the boronized HEA was composed of a great number of borides, including CrB, FeB, MnB, Fe2B, Fe3B and MnB2. The hardness increased from 139 HV to 970 HV after boronizing. In air, the wear rate decreased from 4.51 × 10−4 mm3/Nm to 0.72 × 10−4 mm3/Nm after boronizing. The wear mechanism transformed from abrasive wear and oxidative wear to the polishing effect. After boronizing, in the deionized water, the wear rate decreased from 1.27 × 10−4 mm3/Nm to 8.43 × 10−5 mm3/Nm. The wear mechanism transformed from abrasive wear and delamination wear to delamination wear. In the seawater, the wear rate decreased by about ten times that of hot-rolled alloy.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Peng Li ◽  
Xiya Huang ◽  
Dejun Kong

Purpose The purpose of this paper is to investigate the effects of load and speed on the corrosive wear performance of Al coating in 3.5% NaCl solution, which provided an experimental reference for the anti-corrosion engineering on offshore platforms. Design/methodology/approach A layer of Al coating was prepared on S355 steel using an arc spraying. The corrosive wear test was carried out with CFT–1 type surface property tester. The effects of load and speed on the corrosive wear performance of Al coating were investigated and the wear mechanism was also discussed. The electrochemical tests were conducted using a CHI660E type electrochemical workstation, the anti-corrosion mechanism was analyzed. Findings The average coefficient of frictions (COFs) of Al coating under loads of 1.5, 2.5 and 3.5 N are 0.745, 0.847 and 0.423, the wear mechanism is abrasive wear. The average COFs of Al coating at the speeds of 200, 400 and 600 rpm are 0.745, 0.878 and 0.617, respectively, the wear mechanism at the speeds of 200 and 400 rpm are abrasive wear, while that at the speed of 600 rpm is abrasive wear and fatigue wear. The anti-corrosion mechanism is the isolation of Cl– corrosion and cathodic protection of sacrificial anode. Originality/value This paper mainly studied corrosive wear and electrochemical corrosion performances of Al coating. This study hereby confirms that this manuscript is the original work and has not been published nor has it been submitted simultaneously elsewhere. This paper further confirms that all authors have checked the manuscript and have agreed to the submission.


Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4547
Author(s):  
Bin Yang ◽  
Aiqin Wang ◽  
Kunding Liu ◽  
Chenlu Liu ◽  
Jingpei Xie ◽  
...  

SiCp/Al-Si composites with different CeO2 contents were prepared by a powder metallurgy method. The effect of CeO2 content on mechanical properties, friction and wear properties of the composites was studied. The results show that with the increase in CeO2 content from 0 to 1.8 wt%, the density, hardness, friction coefficient of the composites first increases and then decreases, the coefficient of thermal expansion (CTE) and wear rate of the composites first decreases and then increases. When the content of CeO2 was 0.6 wt%, the density and hardness of the composite reached the maximum value of 98.54% and 113.7 HBW, respectively, the CTE of the composite reached the minimum value of 11.1 × 10−6 K−1, the friction coefficient and wear rate of the composite reached the maximum value of 0.32 and the minimum value of 1.02 mg/m, respectively. CeO2 has little effect on the wear mechanism of composites, and the wear mechanism of composites with different CeO2 content is mainly abrasive wear under the load of 550 N. Compared with the content of CeO2, load has a great influence on the wear properties of the composites. The wear mechanism of the composites is mainly oxidation wear and abrasive wear under low load. With the increase in load, the wear degree of abrasive particles is aggravated, and adhesive wear occurs under higher load.


2020 ◽  
Vol 10 (20) ◽  
pp. 7363
Author(s):  
Lei Xu ◽  
Erkuo Yang ◽  
Yasong Wang ◽  
Changyun Li ◽  
Zhiru Chen ◽  
...  

Ultra high-pressure sintering (UHPS) was used to prepare AA6061/SiCp composites with different contents and the effect of sintering temperatures on microstructure and mechanical properties was investigated in this study. The results showed that a uniform distribution of nano-SiC particles (N-SiCp) is obtained by the UHPS method. With the increase in N-SiCp contents, the higher hardness and better wear resistance could be inspected. The interfacial reactions and Al4C3 phase appeared above 550 °C. The relative density of composites first increased and then decreased; with the temperature raising it reached 99.58% at 600 °C. The hardness and wear property showed the same trend with the hardness reaching 52 HRA and wear rate being 1.0 × 10−6 g/m at 600 °C. Besides, the wear mechanism of the composites is mainly composed of abrasive wear and adhesive wear.


2015 ◽  
Vol 817 ◽  
pp. 571-576
Author(s):  
Jun Tao Zou ◽  
Chan Wang ◽  
Yang Li ◽  
Xian Hui Wang ◽  
Shu Hua Liang

The effect of ambient temperature, materials state and lubrication condition on wear resistance of Cu10Al5Fe5Ni alloy was investigated. The wear surface morphology was characterized by a scanning electron microscope (SEM), and the wear mechanism was discussed as well. The results show that the friction coefficient of Cu10Al5Fe5Ni alloy increases and then decreases with increasing temperature. The wear rate of the Cu10Al5Fe5Ni alloy after solid solution and ageing treatment is less than that of the as-cast alloy, and the wear rate of Cu10Al5Fe5Ni alloy reduces dramatically from 5.31×10-5 mm3 / (m· N) into 1.80×10-6 mm3 / (m·N) after adding lubricating oil. At elevated temperature, the prior wear mechanism is the fatigue wear, accompanying by slight abrasive wear and adhesive wear for the aged Cu10Al5Fe5Ni alloy.


2015 ◽  
Vol 798 ◽  
pp. 424-429
Author(s):  
Xiao Ming Lai ◽  
Jian Chao Han ◽  
Peng Gao ◽  
Jian Jun Qu ◽  
Yun Li ◽  
...  

The wear mechanism of solid lubrication bearing in vacuum environment was researched. It experiment on the angular contact ball bearing of sputter-deposited MoS2 solid lubrication coating in bearing friction test device, and the time-varying characteristics of bearing temperature and vibration can be got. The MoS2 solid lubrication coating on bearing surface was gradually wear in the process of bearing rotation, and the temperature and vibration of bearing were increased. The transfer membrane was formation in bearing raceway with the increase of bearing rotation. The transfer membrane accumulation occurs due to uneven thickness of MoS2 solid lubrication coating, and the bearing produce serious vibration. Through the microstructure observation and energy spectrum analysis of the bearing surface, it finds there are pitting caused by fatigue wear and scratch caused by abrasive wear after test. The test result indicate that the wear mechanism of solid lubrication bearing in vacuum environment were fatigue wear of solid lubrication coating caused by steel ball circularly rolling and abrasive wear caused by steel ball sliding.


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