Study of Microstructure and Wear Behavior of T6 Heat Treated as Cast Al-25Mg2Si-2Cu Alloy

2015 ◽  
Vol 830-831 ◽  
pp. 358-361 ◽  
Author(s):  
D.G. Sondur ◽  
D.M. Goudar ◽  
D.G. Mallapur ◽  
G.B. Rudrakshi

In the present investigation, microstructural characteristics and dry sliding wear behaviour of T6 heat treated conventionally cast Al-25Mg2Si-2Cu alloy have been discussed. The as cast alloy was subjected to solutionizing at 500°C for 5h and isothermal aging treatment at 190°C for different aging times. The micro structural characterization was studied using Scanning Electron Microscope with EDS analysis. The microstructure of as cast alloy consists of intermetallics of coarse block like sharp edged β-(Mg2Si), θ-(Al2Cu) and Q-(Al-Mg-Cu-Si) in the form of Chinese scripts and needles distributed randomly in the Al-matrix. The microstructure of heat treated alloy shows spheroidization of β phase and fine precipitation of θ-(Al2Cu) and Q phases. The dry sliding wear test was carried out using pin-on-disc machine. Age hardened alloy exhibits high wear resistance and minimum coefficient of friction over the entire range of applied loads and sliding velocities. Furthermore, high wear resistance was observed in the under aged condition compared to over ageing conditions.

2017 ◽  
Vol 740 ◽  
pp. 9-16
Author(s):  
Ahmed Sahib Mahdi ◽  
Mohammad Sukri Mustapa ◽  
Mahmod Abd Hakim Mohamad ◽  
Abdul Latif M. Tobi ◽  
Muhammad Irfan Ab Kadir ◽  
...  

The micro-hardness and compression of recycling aluminum alloy AA6061 were investigated as a function of the different microstructure and constituent powder metallurgy method. Five specimens were selected to investigate the compression strength and microhardness. The first, as fabricated specimen (as compacted), the second was as heat treated by quenching and aging process. Three specimens were mixed with Graphite particles as a reinforcement material. Compression strength values were tested for the specimens as fabricated and heat treated which were 195 and 300 MPa, respectively. The improvement ratio was 52% for the specimen as heat treated. On the other hand, high wear resistance was given by the specimen as heat treated, whereas, the lower wear strength was at the specimen mixed with 4.5% Graphite. These results were attributed to that the wear resistance related to the microhardness value.


2011 ◽  
Vol 415-417 ◽  
pp. 707-710
Author(s):  
Hua Chen ◽  
Hai Ying Sun

Fe-based system powder metallurgy in the as-sintered was investigated on pin-on-rolling wear tester for their dry sliding wear behaviour. The morphology of worn surfaces and wear mechanism were analysed by SEM. Results show the hot-forging deformation quenching and tempered considerably decreased the porosity and improved wear resistance, and compare with quenching microstructure, tempered microstructure has high wear resistance and match of strength-toughness. Fe-2.0Ni-0.4Mo-0.5C-0.6Cr alloy presented best wear characteristics. SEM observations of the worn surface revealed microploughing and plastic deformation and crack were the basic dry sliding wear morphology,and oxidative wear and delamination wear are dominant wear mechanism.


Author(s):  
Akshay Shinde

Abstract: To improve the wear resistance of the hybrid powder coating, TiO2 nanoparticles was hot mixed to form a homogenous mixture with the powder in the range varying wt. dry sliding wear test conducted to determine the wear resistance. The experiments were design according to Taguchi L9 array to find the optimum nanoparticles content required to minimize the wear rate of the coating. ANOVA was used to determine the effect of the parameters on wear rate. It showed that reinforcement has the maximum contribution on the wear rate of the coating as compared to load and frequency. From the graph of means optimum parametric values was obtained at 2 % wt of reinforcement, 2 N load and 2 Hz frequency. The wear rate decrease with the increase in reinforcement. Keywords: Taguchi Method, Tribometer, Hybrid powder, TiO2, Wear Rate.


2017 ◽  
Vol 898 ◽  
pp. 355-360
Author(s):  
Hang Li ◽  
Shi Chao Liu ◽  
Jin Chuan Jie ◽  
Ting Ju Li

Special brasses containing Mn and Si possess high wear resistance due to the dispersion of hard Mn5Si3 particles. The effect of precipitation hardening on the wear resistance of a Cu–30Zn–3Al–3Mn–0.7Si based brass alloy was investigated. Dry sliding wear test was conducted using a block-on-ring configuration. The results indicated that finely, nanoscale Mn5Si3 particles precipitated from the matrix after annealing at 800 °C for 4 h, resulting in the increase of hardness from 240 to 278 HV. Both the wear loss and friction coefficient decreased, indicating the improvement of the wear resistance. From the examination of the worn surfaces, adhesive and abrasive wear were found to be the major wear forms. The adhesion and abrasion decreased after the precipitation-hardening treatment.


2015 ◽  
Vol 788 ◽  
pp. 143-150
Author(s):  
Alexandra Gontarenko ◽  
Kai Möhwald ◽  
Todd Alexander Deißer ◽  
Hans Jurgen Maier

Thermal spraying is one of the most efficient methods to deposit hard wear resistant coatings. The coatings deposited by High-Velocity-Oxygen-Fuel spraying (HVOF) are characterized by high wear resistance and outstanding tribological characteristics. One of the most challenging tasks for tribologists is to develop surface treatments that allow for both operating the component without lubricants and at the same time minimize wear. WC-based cermets are a group of thermally sprayed coatings known to have high wear resistance under sliding friction conditions. An experimental study on the dry sliding wear behavior of WCCo HVOF-sprayed coating deposited onto a steel substrate is presented in the current paper. A pin-on-disc tribometer was used to carry out the wear tests.


2012 ◽  
Vol 433-440 ◽  
pp. 572-577
Author(s):  
Hua Chen ◽  
Hai Ying Sun ◽  
Zhan Kui Zhao ◽  
Zhi Long Chai

Fe-Ni-Mo-C-Cr system powder metallurgy in the as-sintered was investigated on pin-on-rolling wear tester for their dry sliding wear behavior. The morphology of worn surfaces and wear mechanism were analysed by SEM. Results show the hot-forging deformation quenching and tempered considerably decreased the porosity and improved wear resistance, and compare with quenching microstructure, tempered microstructure has high wear resistance and match of strength-toughness. Fe-2.0Ni-0.4Mo-0.5C-0.6Cr alloy presented best wear characteristics. SEM observations of the worn surface revealed microploughing and plastic deformation and crack were the basic dry sliding wear morphology,and oxidative wear and delamination wear are dominant wear mechanism.


Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Bingqian Xu ◽  
Jiapeng Sun ◽  
Zhenquan Yang ◽  
Jing Han ◽  
Dan Song ◽  
...  

The microstructure design based on the development of heterostructure provides a new way for high strength and ductility Mg alloys. However, the wear property, as an important service performance, of Mg alloys with heterostructure is scarcely investigated. In this work, a high strength and ductility AZ91 Mg alloy with multiheterostructure was prepared via a processing route combined industrial-scale equal channel angular pressing (ECAP) and aging. The multiheterostructure consists of the heterogeneous grain structure and heterogeneous precipitates. The dry sliding wear behavior of this multiheterostructured (MH) alloy is investigated compared to the as-cast alloy. The impacts of the applied load and duration time on the wear volume and coefficient of friction (COF) are analyzed, and the wear mechanism is further discussed. The result indicates that although the MH alloy exhibits high-desirable strength-ductility synergy, it shows a poorer wear resistance but a relatively lower COF compared to the as-cast alloy at the present condition. The wear mechanism of both alloys mainly involves abrasive wear, as well as mild adhesion, delamination, and oxidation. In comparison, the MH alloy shows relatively severe adhesion, delamination, and oxidation. The poor wear resistance of the MH alloy at the present dry sliding wear condition is linked to the abundant grain boundaries and fine precipitates. Therefore, one should reasonably use the MH Mg alloy considering the service conditions to seek advantages and avoid disadvantages.


Lubricants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 3
Author(s):  
Hamidreza Ghandvar ◽  
Mostafa Abbas Jabbar ◽  
Abdollah Bahador ◽  
Tuty Asma Abu Bakar ◽  
Nor Akmal Fadil ◽  
...  

In current study; the effect of various Gadolinium (Gd) additions on the microstructure and sliding wear behaviour of Al-15%Mg2Si composite before and after the hot extrusion process was examined. Optical microscopy (OM), scanning electron microscopy (SEM) equipped with EDX facility and X-ray diffraction (XRD) were used to characterize the microstructure. The results showed that with addition of 1.0 wt.% Gd to Al-15%Mg2Si composite, the primary Mg2Si particles size reduced from 44 µm to 23 µm and its morphology altered from dendritic to polygonal shape. Further refinement of primary Mg2Si particles was achieved after conducting hot extrusion which resulted in a decrease in its size to 19 µm with a transfer to near-spherical morphology. The Vickers hardness value increased from 55.6 HV in the as-cast and unmodified composite to 72.9 HV in the extruded 1.0% Gd modified composite. The wear test results revealed that composites treated with Gd possess higher wear resistance in comparison with those of without Gd. The highest wear resistance obtained with the lowest wear rates of 0.19 mm3/km and 0.14 mm3/km in the Al-15%Mg2Si-1.0% Gd before and after the hot extrusion, respectively. The high wear resistance of extruded Gd-modified Al-15%Mg2Si composite is due to the refinement of primary Mg2Si particles with uniform distribution in the composite matrix along with fragmentation of Gd intermetallic compounds.


2011 ◽  
Vol 306-307 ◽  
pp. 425-428
Author(s):  
Jing Li ◽  
Xiao Hong Fan ◽  
De Ming Sun

Fe-28Al and Fe-28Al-10Ti alloys were prepared by mechanical alloying and hot pressing. The phases and dry sliding wear behavior were studied. The results show that Fe-28Al bulk materials are mainly characterized by the low ordered B2 Fe3Al structure with some dispersed Al2O3 particles. Fe-28Al-10Ti exhibits more excellent wear resistance than Fe-28Al, especially after long distance sliding wear test. There are obvious differences in wear mechanisms of Fe-28Al and Fe-28Al-10Ti alloys under different testing conditions. Under the load of 100N, there is plastic deformation on the worn surface of Fe-28Al. The main wear performance of Fe-28Al-10Ti is particle abrasion, the characteristics of which are micro cutting and micro furrows, but micro-crack and layer splitting begin to form on the surface of Fe-28Al. Under the load of 200N, serious plastic deformation and work-hardening lead to rapid crack propagation and eventually the fatigue fracture of Fe-28Al. Plastic deformation is the main wear mechanism of Fe-28Al-10Ti under the load of 200N, which are characterized by micro-crack and small splitting from the worn surface.


Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 296 ◽  
Author(s):  
Chao Sun ◽  
Nannan Lu ◽  
Huan Liu ◽  
Xiaojun Wang ◽  
Xiaoshi Hu ◽  
...  

In this study, the dry sliding wear behaviors of SiC particle reinforced AZ91D matrix composites fabricated by stirring casting method were systematically investigated. The SiC particles in as-cast composites exhibited typical necklace-type distribution, which caused the weak interface bonding between SiC particles and matrix in particle-segregated zones. During dry sliding at higher applied loads, SiC particles were easy to debond from the matrix, which accelerated the wear rates of the composites. While at the lower load of 10 N, the presence of SiC particles improved the wear resistance. Moreover, the necklace-type distribution became more evident with the decrease of particle sizes and the increase of SiC volume fractions. Larger particles had better interface bonding with the matrix, which could delay the transition of wear mechanism from oxidation to delamination. Therefore, composites reinforced by larger SiC particles exhibited higher wear resistance. Similarly, owing to more weak interfaces in the composites with high content of SiC particles, more severe delamination occurred and the wear resistance of the composites was impaired.


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