scholarly journals Comparative study on wear behavior of as cast and spray cast hypereutectic Al-Si alloy

2018 ◽  
Vol 27 (3-4) ◽  
Author(s):  
Dayanand M. Goudar ◽  
Mehabubsubahani R. Alavandi ◽  
Saiyad Hasan S. Khaji ◽  
G.B. Rudrakshi ◽  
V.C. Srivastava

AbstractThe microstructure characteristics and wear behavior of a spray-deposited (SD) and the hot compressed Al-28Si alloys were investigated and the results were compared with corresponding SD and as-cast alloys. The microstructure, hardness and wear properties of the spray-deposited alloy was studied using X-ray diffraction, optical microscopy, scanning electron microscopy (SEM), microhardness measurement and wear tests. The microstructures of the SD alloy were composed of refined and uniformly distributed primary silicon (Si) and the formation a fine eutectic phase at the inter particle boundaries of an equiaxed grain morphology of the aluminum (Al) matrix. The decrease in the porosity level and further refinement of primary Si and eutectic Si phases in the hot pressed alloy. The wear tests indicate that the hot pressed spray formed alloy showed good wear resistance compared to both the SD and as-cast alloys. The improvement in the wear behavior is discussed in the light of microstructure evolution by the spray-deposition process. The worn surfaces were characterized by SEM-energy dispersive X-ray spectroscopy (EDS).

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 722
Author(s):  
Morales ◽  
Piamba ◽  
Olaya

We report the results of the influence of the acetylene and oxygen gas pressure on the wear resistance of aluminum–bronze coatings deposited on naval brass substrate by means of the thermal (flame) deposition process. The coatings were characterized by means of scanning electronic microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), and X-ray fluorescence (XRF). The adhesion was determined with cross-hatching tests, and the mechanical response was assessed by measuring the nanohardness and by three-body and ball-on-disk abrasive wear tests. The results indicate that changes in the pressure and flow of the gas affect the morphology and the mechanical properties of the coatings, and these effects have consequences for the wear behavior of the coatings. Before the projection of the coatings, numerical simulations were carried out using Jets & Poudres software, where the collision speed of the particles was identified as the most significant factor that influences the mechanical properties and the performance of the coating. The gas pressure modified the hardness and the porosity level, which allowed improving the wear resistance.


Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 507 ◽  
Author(s):  
Alfredo Morales ◽  
Oscar Piamba ◽  
Jhon Olaya

We report the results of the influence of acetylene and oxygen gas pressure on the corrosion resistance of bronze–aluminum coatings deposited on a naval brass substrate by means of the thermal (flame) deposition process. The coatings were characterized by means of scanning electronic microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), X-ray fluorescence (XRF), and transmission electron microscopy (TEM). The corrosion tests were carried out via Tafel and electrochemical impedance spectroscopy (EIS). In addition, some samples were selected in order to investigate heat treatment and its effects on corrosion resistance. The results indicate that changes in the pressure and flow of the gas affects the composition, morphology, and physical properties of the coatings, and these effects have consequences for the behavior of the coatings when they are immersed in corrosion environments. The collision speed of the particles was identified as the most significant factor that influences the properties and the performance of the coating. The gas pressure modified the oxides and the porosity level, which improved the corrosion resistance.


Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 840 ◽  
Author(s):  
Marzanna Ksiazek ◽  
Lukasz Boron ◽  
Adam Tchorz

In the present work Cr3C2-NiCr powder containing Al particles was deposited on ductile cast iron with high-velocity oxy-fuel (HVOF) thermal spray coating technique. An investigation was conducted to determine the role of Al particles in the Cr3C2-NiCr coating produced with HVOF technique on microstructure, mechanical and wear properties in a system Cr2C3-NiCr coating/ductile cast iron. The microstructure of the HVOF-sprayed Cr3C2-NiCr+Al coating was characterized by light microscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray spectroscopy (EDS). Microstructure analysis reveals the formation of coating with low porosity, good adhesion to the substrate and dense structure with irregularly shaped particles of Al arranged in strips and finely fragmented Cr3C2 particles embedded in a nanocrystalline Ni-Cr alloy matrix. In addition, the results were discussed in reference to examination of bending strength considering cracking and delamination in the system of (Cr3C2-NiCr+Al)/ductile cast iron as well as microhardness and wear resistance of the coating. It was found that the addition of Al particles significantly increased resistance to cracking and wear behaviour in the studied system.


Author(s):  
Deepak Mehra ◽  
M.M. Mahapatra ◽  
S. P. Harsha

The purpose of this article is to enhance the mechanical properties and wear resistance of the RZ5 alloy used in the aerospace application by adding TiC particles. The present study discusses processing of in-situ RZ5-TiC composite fabricated by self-propagating high temperature (S.H.S.) method and its wear behavior. The effects of TiC particle on mechanical and microstructural properties of the composite are studied. The wear test is performed by varying the sliding distance and applied load. The composite is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results exhibited the properties like strength and hardness of RZ5-10wt%TiC composite has been increased considerably, while grain size is decreased as compared to the RZ5 alloy. The fractography indicated mixed mode (quasi-cleavage and ductile feature) failure of the composites. The wear results showed improvement in wear resistance of the composite. The FESEM showed dominate wear mechanisms are abrasion, ploughing grooves.


2015 ◽  
Vol 1120-1121 ◽  
pp. 572-575
Author(s):  
Hong Wei Liu ◽  
Feng Wang ◽  
Qiang Zhang ◽  
Xi Wu Li ◽  
Zhi Hui Li ◽  
...  

An innovative spray deposition technique has been applied to produce in situ TiB2/Zn-30Al-1Cu composites. The microstructures of the spray-deposited composite were studied using optical microscopy, scanning electron microscopy, and X-ray diffraction. Both theoretical and experimental results have shown that the TiB2particulates are formed in the microstructure. It was found that the TiB2particles were distributed in Zn-30Al-1Cu matrix uniformly, and the TiB2particles are about 2 μm in size. Moreover, the presence of the TiB2particles was led to increasing of α’ phase with less 2 μm size in the composites which have a tendency to decompose to α+η structure.


2018 ◽  
Vol 770 ◽  
pp. 106-115
Author(s):  
Jing Wen Qiu ◽  
Di Pan ◽  
Yong Liu ◽  
Ian Baker ◽  
Wei Dong Zhang

The wear behavior of powder metallurgical Ti-47Al-2Cr-0.2Mo alloy prepared by pre-alloyed powders was investigated using pin-on-disk wear tests in different environments, viz, argon, 4% hydrogen in nitrogen, air and oxygen. The disk material was sinter-hot isostatically pressed, yttria-stabilized zirconia. Lower wear rates were found for the TiAl pins in oxygen-free environments, indicating that oxygen play a key role in the wear rate. In contrast, the presence of molecular hydrogen and moisture have nearly no effect. A combination of X-ray diffraction and energy dispersive X-ray spectroscopy indicated that the abrasive particles present mainly consisted of the zirconia. In addition, zirconia particles were embedded in the worn tips of the TiAl pins and mixed into the tribolayers. The high stress and high contact temperature at the wear surface made the zirconia disk undergo a phase transformation during the dry sliding wear, accompanied by grain pullout, surface uplifting and microcracking. The hard tribolayer with embedded zirconia particles provides some protection against further wear of the TiAl pin. The highly localized, repetitive shear stress during the wear tests may bring about amorphous TiAl in the wear debris. The main wear mechanisms were abrasive wear of two-body and three-body, some delamination and plastic deformation.


2014 ◽  
Vol 1015 ◽  
pp. 688-691 ◽  
Author(s):  
Feng Wang ◽  
Qiang Zhang ◽  
Bai Qing Xiong ◽  
Yong An Zhang ◽  
Hong Wei Liu ◽  
...  

An innovative spray deposition technique has been applied to produce in situ TiB2/Zn-30Al-1Cu composites. The microstructures of the spray-deposited composite were studied using scanning electron microscopy, transmission electron microscope and X-ray diffraction. The results have shown that the TiB2particulates are formed in the microstructure. It was found that the TiB2particles were distributed in Zn-30Al-1Cu matrix uniformly, and the TiB2particles are about 2μm in size.


2013 ◽  
Vol 685 ◽  
pp. 112-116 ◽  
Author(s):  
K.G. Basava Kumar

The microstructures and dry sliding wear behavior of Al-17Si cast alloys were studied after various melt treatments such as refinement and modification. Results indicate that combined refined and modified Al-17Si cast alloys have microstructures consisting of uniformly distributed primary silicon and fine eutectic AlSilicon particles through out the matrix. These alloys exhibited better wear resistance in the cast condition compared with the same alloy subjected to only refinement or modification. The improvements in properties observed in the present studies are mainly due to the structural differences between the refined, modified or both refined and modified over just cast Al-Si alloys. This paper attempts to investigate the influence of the microstructural changes in the Al-17Si cast alloys by refinement, modification and combined action of both on the dry sliding wear behavior.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4072
Author(s):  
Mihail Lungu ◽  
Ioana Porosnicu ◽  
Paul Dinca ◽  
Alin Velea ◽  
Flaviu Baiasu ◽  
...  

Reduced activation ferritic and martensitic steel like EUROFER (9Cr-1W) are considered as potential structural materials for the first wall of the future next-generation DEMOnstration Power Station (DEMO) fusion reactor and as a reference material for the International Thermonuclear Experimental Reactor (ITER) test blanket module. The primary motivation of this work is to study the re-deposition of the main constituent materials of EUROFER, namely tungsten (W), iron (Fe), and chromium (Cr), in a DEMO type reactor by producing and analyzing complex WxCryFe1−x−y layers. The composite layers were produced in laboratory using the thermionic vacuum arc (TVA) method, and the morphology, crystalline structure, elemental composition, and mechanical properties were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-X-ray fluorescence (micro-XRF), and glow discharge optical emission spectrometry (GDOES), as well as nanoindentation and tribology measurements. The results show that the layer morphology is textured and is highly dependent on sample positioning during the deposition process. The formation of polycrystalline WxCryFe1−x−y was observed for all samples with the exception of the sample positioned closer to Fe anode during deposition. The crystalline grain size dimension varied between 10 and 20 nm. The composition and thickness of the layers were strongly influenced by the in-situ coating position, and the elemental depth profiles show a non-uniform distribution of Fe and Cr in the layers. The highest hardness was measured for the sample positioned near the Cr anode, 6.84 GPa, and the lowest was 4.84 GPa, measured for the sample positioned near the W anode. The tribology measurements showed an abrasive sliding wear behavior for most of the samples with a reduction of the friction coefficient with the increase of the normal load.


2017 ◽  
Vol 62 (4) ◽  
pp. 2001-2006
Author(s):  
S. Islak

AbstractIn this study, wear properties of FeW-B4C coatings produced by tungsten inert gas (TIG) process on the AISI 1060 steel were investigated. TIG process was selected because it is a cost-effective approach for melting-based coatings. The treated surfaces were evaluated and characterized by means of scanning electron microscope (SEM), X-ray diffraction analysis, and electron dispersive spectrometry (EDS). The microhardness and wear experiment were also performed by using a microhardness machine and ball-on-disk tribometer. SEM observations showed that the obtained coating had a smooth and uniform surface. According to XRD analysis, borides and carbides phases formed in the coatings. The wear behavior of the coatings was compared with ball-on-disc configuration wear tests, at the same conditions. Average coefficient of friction values of the coatings were obtained at relatively low levels.


Sign in / Sign up

Export Citation Format

Share Document