scholarly journals MICROSTRUCTURAL CHARACTERISTICS, MECHANICAL AND WEAR BEHAVIOUR OF ALUMINIUM-ALLOYED DUCTILE IRONS SUBJECTED TO TWO AUSTEMPERING PROCESSES

2020 ◽  
Vol 60 (3) ◽  
pp. 185-196
Author(s):  
Abdullahi Olawale Adebayo ◽  
Akinlabi Oyetunji ◽  
Kenneth Kenayo Alaneme
Keyword(s):  
Wear Resistance ◽  
Intermetallic Compound ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Dominant Role ◽  
Melting Furnace ◽  
Wear Behaviour ◽  
Wear Properties ◽  
The Matrix ◽  
Aluminium Addition

The effect of aluminium addition and austempering processes on the microstructures, mechanical and wear properties of rotary melting furnace processed ductile irons was investigated. Ductile irons containing 1−4 wt.% Al were produced and subjected to single and two-step austempering processes. Optical microscopy was used to characterize the graphite features and estimate the volume fraction of the matrix phases present, while the x-ray diffractogram was also carried out to analyse the samples. Mechanical and wear properties of the alloys were equally evaluated. From the results, it was observed that both the as-cast and austempered ductile iron microstructures contained nodular graphite, and the matrix structure for the as-cast ductile irons consisted predominantly of pearlite and ferrite, while that of the austempered grades, contained principally, ausferrite. The microstructure and intermetallic compound obtained played dominant role on the properties of the alloys. The aluminium addition and austempering processes had a significant influence on the mechanical properties and wear resistance of the alloys. The austempered ductile irons exhibited superior strength and wear resistance compared to the as-cast samples, albeit ductility values were lower in the composition group. Austempering increased the strength by over 100% while the addition of Al further enhanced the strength. The improved properties were linked to the refined microstructure, increased proportion of ausferrite phase and intermetallic compound formed. For all properties evaluated, the two-step austempering yielded better properties combination than the single step process. The rotary melting furnace processing adopted was found viable for ductile iron production.

Enhanced Tensile and Wear Properties of CFRP Composites Manufactured Using Vacuum Infusion Process

2019 ◽  
Vol 969 ◽  
pp. 271-277
Author(s):  
Syam Kumar Chokka ◽  
Beera Satish Ben ◽  
K.V. Sai Srinadh
Keyword(s):  
Tensile Strength ◽  
Wear Resistance ◽  
Volume Fraction ◽  
Longitudinal Direction ◽  
Wear Behaviour ◽  
Wear Properties ◽  
Fiber Volume ◽  
Vacuum Infusion ◽  
Cfrp Composites ◽  
Vacuum Infusion Process

The properties of a composite are depending on the manufacturing process, fiber and its configuration, epoxy used etc. The present research deals with the tensile and wear behaviour of the composites manufactured using Hand Layup (HL) and Vacuum Infusion Process (VIP) with structural and non-structural epoxy combination. 4-layerd (all the layers are oriented in the longitudinal direction) unidirectional CFRP was manufactured using VIP and those results were compared with the HL made samples. The addition of structural epoxy in the resin mixer have shown a significant effect on its fiber volume fraction, tensile and erosion properties. The effect of vacuum pressure in mould cavity on the tensile strength of the CFRP composite was also studied. The morphologies of the CFRP composites made with VIP and HL were studied with the help of the scanning electron microscopy (SEM). The CFRP composites manufactured through VIP have shown a greater tensile strength but it was poor in wear resistance. The addition of structural adhesive to the resin system enhanced the wear resistance. Hence it made the VIP a recommended process for composite manufacturing where both tensile and wear properties are required.

Microstructure and Properties of Fe-B-C Cast Wear-Resistant Alloy

2017 ◽  
Vol 732 ◽  
pp. 59-68 ◽  
Author(s):  
Zhi Fu Huang ◽  
Jian Dong Xing ◽  
Sheng Qiang Ma ◽  
Yi Min Gao ◽  
Ming Zheng ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Carbon Content ◽  
Boron Content ◽  
Volume Fraction ◽  
Dominant Role ◽  
Wear Test ◽  
Wear Resistant ◽  
Resistant Alloy ◽  
The Matrix ◽  
The Impact

The microstructure, toughness, hardness and wear resistance of Fe-B-C cast wear-resistant alloy were studied. The results indicate that, the as-cast Fe-B-C alloy comprises pearlite, ferrite and eutectic phase Fe2 (B, C), and that, with increasing boron and carbon contents, the boride volume fraction (BVF) and macrohardness increase; furthermore, when boron content increases from about 0.5 wt.% to 2.0 wt.%, the increase trend of the macrohardness will become smaller with increasing the carbon content. The results also indicate that, after heat-treatment, the Fe2 (B, C) becomes coarser than that as cast condition, and the boron content has less effect on the martensite hardness at the same carbon content; with increasing boron and carbon contents, the hardness of the samples increases and inversely the toughness decreases. At a lower BVF, the matrix plays a dominant role on the impact toughness of Fe-B-C alloy; however, at a higher BVF, the BVF plays a dominant role. The wear test results indicate that, with increasing the boron and carbon contents, the weight loss of the samples decreases, namely, the increase of wear resistance.

scholarly journals Comparison of Structure and Properties of Mo2FeB2-Based Cermets Prepared by Welding Metallurgy and Vacuum Sintering

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 46
Author(s):  
Hu Xu ◽  
Junsheng Sun ◽  
Jun Jin ◽  
Jijun Song ◽  
Chi Wang
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Volume Fraction ◽  
Phase Evolution ◽  
304 Stainless Steel ◽  
Vacuum Sintering ◽  
Cored Wire ◽  
Welding Metallurgy ◽  
Metallurgical Bonding ◽  
The Matrix

At present, most Mo2FeB2-based cermets are prepared by vacuum sintering. However, vacuum sintering is only suitable for ordinary cylinder and cuboid workpieces, and it is difficult to apply to large curved surface and large size workpieces. Therefore, in order to improve the flexibility of preparing Mo2FeB2 cermet, a flux cored wire with 70% filling rate, 304 stainless steel, 60 wt% Mo powder and 40 wt% FeB powder was prepared. Mo2FeB2 cermet was prepared by an arc cladding welding metallurgy method with flux cored wire. In this paper, the microstructure, phase evolution, hardness, wear resistance and corrosion resistance of Mo2FeB2 cermets prepared by the vacuum sintering (VM-Mo2FeB2) and arc cladding welding metallurgy method (WM-Mo2FeB2) were systematically studied. The results show that VM-Mo2FeB2 is composed of Mo2FeB2 and γ-CrFeNi.WM-Mo2FeB2 is composed of Mo2FeB2, NiCrFe, MoCrFe and Cr2B3. The volume fraction of hard phase in WM-Mo2FeB2 is lower than that of VM-Mo2FeB2, and its hardness and corrosion resistance are also slightly lower than that of VM-Mo2FeB2, but there are obvious pores in the microstructure of VM-Mo2FeB2, which affects its properties. The results show that WM-Mo2FeB2 has good diffusion and metallurgical bonding with the matrix and has no obvious pores. The microstructure is compact and the wear resistance is better than that of VM-Mo2FeB2.

scholarly journals Role of titanium carbide and alumina on the friction increment for Cu-based metallic brake pads under different initial braking speeds

Friction ◽  
2020 ◽  
Author(s):  
Tao Peng ◽  
Qingzhi Yan ◽  
Xiaolu Zhang ◽  
Yan Zhuang
Keyword(s):  
Wear Resistance ◽  
Titanium Carbide ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Interface Bonding ◽  
Brake Pads ◽  
Reinforced Composite ◽  
The Poor ◽  
The Matrix

AbstractTo understand the effect of abrasives on increasing friction in Cu-based metallic pads under different braking speeds, pad materials with two typical abrasives, titanium carbide (TiC) and alumina (Al2O3), were produced and tested using a scale dynamometer under various initial braking speeds (IBS). The results showed that at IBS lower than 250 km/h, both TiC and Al2O3 particles acted as hard points and exhibited similar friction-increasing behavior, where the increase in friction was not only enhanced as IBS increased, but also enhanced by increasing the volume fraction of the abrasives. However, at higher IBS, the friction increase was limited by the bonding behavior between the matrix and abrasives. Under these conditions, the composite containing TiC showed a better friction-increasing effect and wear resistance than the composite containing Al2O3 because of its superior particle-matrix bonding and coefficient of thermal expansion (CTE) compatibility. Because of the poor interface bonding between the matrix and Al2O3, a transition phenomenon exists in the Al2O3-reinforced composite, in which the friction-increasing effect diminished when IBS exceeded a certain value.

Study on the Wear Resistance of Cast-Oozing Different Content of WC

2011 ◽  
Vol 239-242 ◽  
pp. 990-993
Author(s):  
Ai Qin Wang ◽  
Shu Li Wang ◽  
Jing Pei Xie
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Iron Layer ◽  
Wear Properties ◽  
Metallurgical Bonding ◽  
The Matrix ◽  
Different Content

In this paper, the WC and high-Cr Cast Iron layer were obtained on the surface of ZG30Cr steel by casting-penetrating process, the organization and wear properties of penetrating layer were studied. The results show that the layer is dense, without pores, slag and other defects, the penetrating layer and substrate are metallurgical bonding. When 20 %WC and 80 % Cr-Fe with are added to permeability agent, the penetrating layer has the best wear resistance, is 11.3 times the matrix materials.

Metal-matrix composite fabricated with gas tungsten arc melt injection and precoated with NiCrBSi alloy to increase the volume fraction of WC particles

2017 ◽  
Vol 24 (2) ◽  
pp. 195-202 ◽  
Author(s):  
Aiguo Liu ◽  
Da Li ◽  
Fanling Meng ◽  
Huanhuan Sun
Keyword(s):  
Wear Resistance ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Low Carbon Steel ◽  
High Volume ◽  
Wear Loss ◽  
Low Carbon ◽  
Gas Tungsten Arc ◽  
The Matrix ◽  
Gas Tungsten

AbstractThe volume fraction, dissolution, and segregation of WC particles in metal-matrix composites (MMCs) are critical to their wear resistance. Low carbon steel substrates were precoated with NiCrBSi coatings and processed with gas tungsten arc melt injection method to fabricate MMCs with high volume fraction of WC particles. The microstructures and wear resistance of the composites were investigated. The results showed that the volume fraction of WC particles increased with decreasing hopper height and was as high as 44% when hopper height was 100 mm. The dissolution of WC particles was minimal. The content of the alloying elements decreased from the top to the bottom of the matrix. More WC particles dissolved in the overlapping area, where Fe3W3C carbide blocks could be found. The wear loss of the MMCs after 40 min was 6.9 mg, which is 76 times less than that of the substrate after the 4 min test.

Wear Behaviour of HVOF Sprayed WC-Cobalt Coatings

2011 ◽  
Vol 326 ◽  
pp. 144-150
Author(s):  
A. Mateen ◽  
Fazal Ahmad Khalid ◽  
T.I. Khan ◽  
G.C. Saha
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
High Hardness ◽  
Wear Behaviour ◽  
Wear Properties ◽  
Coating Structure ◽  
Superior Mechanical Properties ◽  
Cobalt Coating ◽  
Mining Tools ◽  
Duplex Coatings

Tungsten carbide cobalt coating has been extensively used for cutting and mining tools, aerospace, automotive and other wear resistance applications. These coatings not only have superior mechanical properties like high hardness, toughness and compressive strength but have also excellent controllable tribological properties. In this paper a comparison of wear properties and structural phases has been presented to consider for tribological applications. It is found that nanocrystalline duplex coatings have shown much superior properties as compared to the microcrystalline coatings. Evidence of clusters of WC particles was found in microcrystalline coating as compared to homogeneous dense coating structure observed in the nanocrystalline coating. These results are discussed to assess their suitability for super hard wear resistance applications.

MICROSTRUCTURE AND WEAR PROPERTIES OF LASER CLAD TiB2 + TiC/Fe COMPOSITE COATING

2012 ◽  
Vol 19 (05) ◽  
pp. 1250052 ◽  
Author(s):  
X. H. WANG ◽  
M. ZHANG ◽  
B. S. DU ◽  
S. LI
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Volume Fraction ◽  
Composite Coatings ◽  
Wear Properties ◽  
Friction Coefficients ◽  
Iron Based

Iron-based composite coatings reinforced with TiB2–TiC multiple ceramic have been fabricated from a precursor of B4C , TiO2 and Al powders by laser cladding. The effect of TiO2 and Al on the microstructure and wear properties of the coatings was investigated. The results showed that the volume fraction, type and size of the reinforcements were influenced by the content of TiO2 and Al . TiB2 and TiC were evenly distributed in the coating; however, most of Al2O3 were ejected from the coatings, only few of them retained in the coating acting as nucleation core of reinforcement or inclusion. The microhardness and wear resistance of the coatings were improved, whereas the friction coefficients of the coatings were considerably lower than that of substrate.

scholarly journals Investigation of Wear Behaviour of Al6061 reinforcement with TiC and MoS2

2017 ◽  
Vol 13 (3) ◽  
pp. 32-36
Author(s):  
S. Rajesh ◽  
C. Velmurugan
Keyword(s):  
Wear Resistance ◽  
Volume Fraction ◽  
Wear Behavior ◽  
Aluminum Matrix ◽  
Cost Effective ◽  
Stir Casting ◽  
Wear Behaviour ◽  
Dry Sliding Wear ◽  
Specific Strength ◽  
Main Challenge

Metal matrix composite (MMC) focuses primarily on improved specific strength, high temperature and wear resistance application. Aluminum matrix reinforced with titanium carbide and molybdenum disulfide has good potential and also self-lubrication. The main challenge is to produce this composite in a cost effective way to meet the above requirements. In this study Al–TiC-MoS2 castings with different volume fraction of TiC and MoS2 were produced in an argon atmosphere by an enhanced stir casting method. Hardness of the composite has increased with higher % of TiC addition. At that same time self-lubrication of composite has occur in the effort of MoS2. Dry sliding wear behavior of AMC was analyses with the help of a pin on disc wear and friction monitor. The present analyses reveal the improved hardness  as well as wear resistance.

scholarly journals The Effect of Palm Kernel Shell Ash on the Mechanical and Wear Properties of White Cast Iron

2020 ◽  
Vol 45 (2) ◽  
pp. 20-27
Author(s):  
Kayode I. Fesomade ◽  
Damilola D. Alewi ◽  
Saliu O. Seidu ◽  
Sheriff O. Saka ◽  
Bonaventure I. Osuide ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Cast Iron ◽  
Elemental Composition ◽  
White Cast Iron ◽  
Palm Kernel ◽  
Rotary Furnace ◽  
Wear Properties ◽  
Palm Kernel Shell ◽  
The Matrix

This study investigates the influence of palm kernel shell ash (PKSA) on mechanical and wear properties of white cast iron (WCI) particularly its influence on its microstructure, elemental composition, hardness and wear resistance. The PKSA was characterized to determine its elemental composition, and it was found to contain high amount of silicon (Si) and iron (Fe) followed by calcium (Ca) and other trace elements. The cast iron was cast into rods of specific dimension with sand casting method using rotary furnace to re-melt cast iron scrap. The WCI rods were then cut into bits for the various test. Heat treatment operation was carried out to determine its properties. Upon completion of the examinations, it was found that the PKSA increased the cementite phase within the matrix of the cast iron, and reduced the pearlitic phase and graphite formation, which gave it increased hardness, and perfect wear resistance due to the increment in carbon content and reduction in silicon content. Also, upon heat treatment, it was found that the PKSA reduced the pearlitic phase within the matrix of the cast iron, increases the formation of transformed ledeburites, austenitic dendrites and tempered graphite, which lead to increased machinability and ductility as well as to reduced hardness, and wear resistance when compared to non-heat treated samples.

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