Elevated-Temperature Wear Characteristics and Mild-Severe Wear Transition in the Mg–10.1Gd–1.4Y–0.4Zr Alloy

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
J. An ◽  
W. Zhao ◽  
C. Q. Feng
Keyword(s):  
Elevated Temperature ◽  
Surface Temperature ◽  
Test Temperature ◽  
Elevated Temperatures ◽  
Testing Machine ◽  
Wear Testing ◽  
Critical Surface ◽  
Severe Wear ◽  
Wear Characteristics ◽  
Wear Transition

Abstract Dry sliding wear characteristics of the as-cast Mg–10.1Gd–1.4Y–0.4Zr alloy were investigated at 3.0 m/s within a temperature range of 20–200 °C on a pin-on-disc type wear testing machine. Wear rates were acquired and plotted against load at each test temperature. There existed a turning point on the wear rate versus load curve at each test temperature; it corresponded to the mild-severe wear transition. The wear mechanisms were confirmed through morphological and compositional analysis of worn surfaces. An elevated-temperature wear mechanism transition map was drawn, in which mild and severe wear regions were indicated. The differences in microstructure as well as microhardness in subsurfaces were compared between samples worn in the two different regions. The dynamic recrystallization (DRX) softening of the surface material was found to be responsible for mild-severe wear transition. An approximately linear relationship was found between the transition load and test temperature, suggesting that mild-severe wear transition of the alloy still follows a surface temperature criterion even at elevated temperatures. The critical surface temperature is thought of to be the DRX temperature of the alloy. It is approximately 279.3 °C based on the linearly fitting analysis of the transition load versus test temperature.

scholarly journals Dry Sliding Wear Behavior and Mild–Severe Wear Transition of Mg97Zn1Y2 Alloy at Elevated Temperatures

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1735 ◽  
Author(s):  
Liang Li ◽  
Jihe Feng ◽  
Ce Liang ◽  
Jian An
Keyword(s):  
Test Temperature ◽  
Sliding Wear ◽  
Elevated Temperatures ◽  
Wear Behavior ◽  
Hardness Measurement ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Softening Effect ◽  
Severe Wear ◽  
Wear Transition

Dry sliding wear behavior of Mg97Zn1Y2 alloy was investigated at test temperatures of 50–200 °C under three sliding speeds of 0.8 m/s, 3.0 m/s and 4.0 m/s. The wear mechanisms in mild and severe wear regimes were identified by examination of morphologies and compositions of worn surfaces using scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDS), and from which wear transition maps under different sliding speeds were constructed on rectangular coordinate systems with applied load versus test temperature axes. It is found that under each sliding speed condition, mild–severe transition load decreases almost linearly within the test temperature range of 50 °C to 200 °C. Microstructure observation and hardness measurement in subsurfaces identify that the softening effect generating form dynamic crystallization (DRX) is the dominant mechanism for the mild–severe wear transition at elevated temperatures. The mild–severe wear transition at 50–200 °C follows the contact surface DRX temperature criterion, and the transition loads can be well evaluated using the criterion.

scholarly journals Masking Effect of LPSO Structure Phase on Wear Transition in Mg97Zn1Y2 Alloy

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1857
Author(s):  
Fujun Tao ◽  
Hongfei Duan ◽  
Lijun Zhao ◽  
Jian An
Keyword(s):  
Wear Rate ◽  
Elevated Temperatures ◽  
Wear Behavior ◽  
Testing Machine ◽  
Masking Effect ◽  
Enhancement Effect ◽  
Severe Wear ◽  
Lpso Structure ◽  
Structure Phase ◽  
Wear Transition

Room- and elevated-temperature wear tests were conducted using a pin-on-disk testing machine to study wear behavior of Mg97Zn1Y2 alloy and role of long-period-stacking-ordered (LPSO) structure phase in mild–severe wear transition (SWT). Variation of wear rate exhibited a three-stage characteristic with load at various test temperatures, i.e., a gradual increasing stage, a slightly higher plateau stage, and a rapid rising stage. The wear mechanisms in the three stages were identified using scanning electron microscope (SEM), from which the first stage was confirmed as mild wear, and the other two stages were verified as severe wear. The interdendritic LPSO structure phase was elongated into strips along the sliding direction with Mg matrix deformation in the subsurface, plate-like LPSO structure phase precipitated at elevated temperatures of 150 and 200 °C. The fiber enhancement effect and precipitation effect of LPSO structure phase resulted in a little difference in wear rate between the first and second stages, i.e., a masking effect on SWT. Microstructure and microhardness were examined in the subsurfaces, from which the mechanism for SWT was confirmed to be dynamic recrystallization (DRX) softening. There is an apparently linear correlation between the critical load for SWT and test temperature, indicating that SWT is governed by a common critical DRX temperature.

Study on Tribology Characteristic of the Cast Iron Friction Pair in the Self-Repairing Additive and Mechanism Analyzing

2011 ◽  
Vol 239-242 ◽  
pp. 1896-1900
Author(s):  
Yan Hong Yan ◽  
Yu Lin Yang ◽  
Nan Wang
Keyword(s):  
Cast Iron ◽  
Friction Pair ◽  
Testing Machine ◽  
Great Influence ◽  
The Self ◽  
Wear Testing ◽  
Wear Characteristics ◽  
Remarkable Effect ◽  
Frictional Wear ◽  
Self Repair

Influence of frictional wear characteristics of the cast iron-cast iron friction pair were investigated in the Self-repairing Additive with different concentration by using MMU-5G end-face friction and wear testing machine. The capability of generating self-repair coatings on the cast iron tribo-surface was verified in the Self-repairing Additive. The surface images of friction pair and their chemical composition were detected by using SEM and EDS. The result indicates different concentration has a great influence on frictional wear characteristics of friction pair in the Self-repairing Additive. In the self-repairing Additive, the Self-repair coatings are not formed on the cast-iron worn surface; self-repairing Additive has remarkable effect on antifriction and wearing of cast iron.

An Experimental Study of Friction and Wear Characteristics of Sunflower and Soybean Oil Methyl Ester Under the Steady-State Conditions by the Four-Ball Wear Testing Machine

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Mahmoud Amiri Nazari Barsari ◽  
Alireza Shirneshan
Keyword(s):  
Steady State ◽  
Soybean Oil ◽  
Diesel Engines ◽  
Internal Combustion Engines ◽  
Friction And Wear ◽  
Testing Machine ◽  
Wear Testing ◽  
Steady State Condition ◽  
Wear Characteristics ◽  
Fuel Blends

According to that the fuel pump and injectors of the diesel engines are lubricated by the fuel itself, so the lubrication property of the fuels is an important issue in internal combustion engines. Biodiesel is one of the most famous biofuels that can be used in diesel engines. In this research, wear characteristics of biodiesel derived from sunflower and soybean oil blends were investigated. The five fuel blends were tested under steady-state conditions (with durations of 1500 and 3600 s) at four different rotational speeds of 600, 900, 1200, and 1500 rpm. An optical microscope was also applied to check out the worn surfaces of the balls. The results indicated that wear and friction as tribological properties were reduced with the increase in the rotating speed under the steady-state condition. It was found that with an increase in the biodiesel concentration, the friction coefficient was reduced at lower rotating speeds due to free fatty acids, monoglycerides, and diglycerides as the components of biodiesel which help improve the lubrication properties of biodiesel and reduce the friction more than that of other blends. However, in higher rotational speeds, friction and wear of fuel blends included biodiesel increased due to reduced viscosity as the causes of oxidation which helps in the exposure of biodiesel to air at higher temperature. So, B100 has better lubricity properties compared to other fuel blends at lower rotational speeds, and better performance belongs to B20 at higher rotational speeds.

Effect of test temperature on dry sliding wear behavior and mild-severe wear transition of Mg97Zn1Y2 alloy

2019 ◽  
Vol 6 (4) ◽  
pp. 046545
Author(s):  
Liang Li ◽  
Changqin Feng ◽  
Wei Zhao ◽  
Ce Liang ◽  
Jian An
Keyword(s):  
Test Temperature ◽  
Sliding Wear ◽  
Wear Behavior ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Severe Wear ◽  
Wear Transition

scholarly journals An Experimental Research On Friction And Wear Behaviour Of Compact Graphite Iron At Elevated Temperatures

2019 ◽  
Vol 8 (2S11) ◽  
pp. 2630-2633
Keyword(s):  
Friction And Wear ◽  
Thermal Stresses ◽  
Elevated Temperatures ◽  
Testing Machine ◽  
Wear Testing ◽  
Wear Behaviour ◽  
Compact Graphite Iron ◽  
Compact Graphite ◽  
Pin On Disc ◽  
Frictional Forces

Compact Graphite iron (CGI) is mainly used in automobile engine cylinder blocks and disc brakes. CGI has interconnected by vermicular shape graphite. Melting of steel and treatment of CGI is useful for getting sound castings. In automobiles the components manufactured by CGI are exposed to friction including wear, abrasion, thermal stresses and fatigue. Friction and wear characteristics at elevated temperatures are studied in the present study. Friction tests on CGI are conducted with pin on disc wear testing machine between CGI and hard steel disc. The deviations in frictional forces and wear behaviour are observed from the experimental results. The results shows that the wear rate and frictional forces of CGI at 400°C and 500°C temperatures was strongly influenced by the variation in induced temperatures. Scanning Electron Microscopy (SEM) is used to examine CGI pins surfaces. Temperature variations during experiments are influenced the CGI coefficient of friction.

Strength of Adhesive T-Joint in Granulator Fluidization Bed at Elevated Temperature

2015 ◽  
Vol 819 ◽  
pp. 443-448 ◽  
Author(s):  
Basirom Izzawati ◽  
M. Afendi ◽  
S. Nurhashima ◽  
A. Nor ◽  
A.R. Abdullah ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Room Temperature ◽  
Adhesive Bonding ◽  
Elevated Temperatures ◽  
Testing Machine ◽  
Perforated Plate ◽  
Adhesively Bonded ◽  
Loading Tests ◽  
Bondline Thickness

This paper presents the results of an experimental investigation on mechanical characterization of adhesive T-joint in granulator fluidization bed at elevated temperature. This research aims to explore the suitability of adhesive bonding between stainless steel plate and perforated plate to replace plug weld in granulator fluidization bed. For this purpose, T-joint and bulk specimens were prepared for tensile loading tests, at different temperature. Measurement of the temperature-dependent of the tensile strength was conducted using thermostatic chamber attached to a universal testing machine for a range from room temperature to 100°C. The strength of adhesive T-joint decreases for temperatures over than 35°C. This is because at high temperature, the failure is determined by the changes of mechanical properties of adhesive. The results have shown that the strength of adhesive T-joint was affected by both temperature and bondline thickness. The objective of the present study was to examine a series of adhesively-bonded T-joints in tension at elevated temperatures between room temperature and 100°C having various bond thicknesses.

Influence on Tribology Characteristic of the Steel-Cast Iron Friction Pair under Different Concentration of the Self-Repairing Additive and Mechanism Analyzing

2011 ◽  
Vol 189-193 ◽  
pp. 1085-1090
Author(s):  
Yan Hong Yan ◽  
Yu Lin Yang ◽  
Dan Zhang
Keyword(s):  
Cast Iron ◽  
Friction Pair ◽  
Testing Machine ◽  
Great Influence ◽  
The Self ◽  
Wear Testing ◽  
Wear Characteristics ◽  
Frictional Wear ◽  
Self Repair ◽  
Worn Surface

The influence of frictional wear characteristics were investigated under the Self-repairing Additive condition with different concentration by using MMU-5G end-face friction and wear testing machine. The surface images of friction pair and their chemical composition were detected by using SEM and EDS. The result indicates different concentration has a great influence on frictional wear characteristics of friction pair. The Self-repair coatings are formed on the 45#steel worn surface while nothing on the cast-iron worn surface, study considers that metallographic structure and mechanical performance of cast iron are the prime causation resulting in no Self-repair coatings. Self-repairing Additive of the right concentration has remarkable effect on antifriction and wearing of cast iron.

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