Comparison of the mechanical and wear behaviour of aluminium alloy with homogeneous and functionally graded silicon nitride composites

2018 ◽  
Vol 25 (2) ◽  
pp. 261-271 ◽  
Author(s):  
N. Radhika
Keyword(s):  
Silicon Nitride ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Outer Surface ◽  
Centrifugal Casting ◽  
Functionally Graded ◽  
Wear Behaviour ◽  
Unreinforced Alloy ◽  
Functionally Graded Composite ◽  
Uniform Dispersion

AbstractHomogeneous and functionally graded LM25 aluminium (Al) composites were fabricated by incorporating silicon nitride (10 wt%, 40 µm) particles through liquid metallurgy and centrifugal casting, respectively. The performance of these composites was compared with unreinforced alloy. The microstructural behaviour of the surfaces of unreinforced alloy, homogeneous composite and functionally graded composite (outer, middle and inner surfaces) were examined through optical microscopy. These surfaces were also evaluated for mechanical properties. An abrasive wear test was conducted on all these surfaces to determine their effect on wear rate. The microstructural results revealed a particle-rich region at the outer surface of the functionally graded composite material and uniform dispersion of reinforcement particles in the homogeneous composite. The outer region of the functionally graded composite showed greater hardness and the homogeneous composite displayed higher tensile strength. The abrasive wear rate increased with an increase in load and decreased with an increase in speed, and the particle-rich outer surface showed a lower wear rate. Scanning electron microscopy analysis revealed a particle-rich outer surface of functionally graded composite with fewer scratches. Therefore, higher wear resistance was observed at the outer periphery of functionally graded composites and this property can be well-utilised in automotive tribo-components such as in cylinder liners for improved performance.

Parametric Study of Dry Sliding Wear Behaviour of Functionally Graded Al LM25/Si3N4 Composite by Response Surface Methodology

2015 ◽  
Vol 24 (6) ◽  
pp. 096369351502400 ◽  
Author(s):  
N. Radhika ◽  
R. Raghu
Keyword(s):  
Response Surface Methodology ◽  
Wear Rate ◽  
Response Surface ◽  
Outer Surface ◽  
Sliding Wear ◽  
Centrifugal Casting ◽  
Functionally Graded ◽  
Wear Behaviour ◽  
Inner Surface ◽  
Sliding Distance

Functionally graded aluminium LM25/silicon nitride composite was produced through stir casting followed by centrifugal casting and obtained a hollow cylindrical cast component with dimensions of 150 × 150 × 20 mm. The microstructural examination and the hardness test were carried out on the outer (1 mm) and inner surface (17 mm) as the function of radial distance from the outer periphery. The outer surface was observed with particle enriched region compared to inner surface and exhibited higher hardness. Hence the outer surface of the functionally graded composite was only further subjected to sliding wear test in pin-on-disc tribometer. The Central Composite Design in Response Surface Methodology was used to design the experiments for the selected parameters such as load (15–45 N), velocity (0.5–2.5 m/s) and sliding distance (500–2000 m). Regression test and Analysis of Variance were conducted to check the adequacy of the constructed model. The surface plots for wear rate showed that wear rate increased with increase in load and non-linearly varied with increase in velocity and sliding distance. Scanning Electron Microscopy analysis was conducted on the worn-out surfaces and observed mild to severe wear transition on increase of load.

Enhancing the tensile strength of SiC reinforced aluminium- based functionally graded structure through the mixture design approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
M. Poornesh ◽  
Shreeranga Bhat ◽  
E.V. Gijo ◽  
Pavana Kumara Bellairu
Keyword(s):  
Tensile Strength ◽  
Composite Structure ◽  
Centrifugal Casting ◽  
Matrix Material ◽  
Stir Casting ◽  
Mixture Design ◽  
Functionally Graded ◽  
Content Type ◽  
Functionally Graded Composite ◽  
The Matrix

PurposeThis article aims to study the tensile properties of a functionally graded composite structure with Al–18wt%Si alloy as the matrix material and silicon carbide (SiC) particles as the reinforcing element. More specifically, the study's primary objective is to optimize the composition of the material elements using a robust statistical approach.Design/methodology/approachIn this research, the composite material is fabricated using a combination of stir casting and the centrifugal casting technique. Moreover, the test specimen required to study the tensile strength are prepared according to the ASTM (American Society for Testing and Materials) standards. Eventually, optimal composition to maximize the tensile property of the material is determined using the mixture design approach.FindingsThe investigation results imply that the addition of the SiC plays a crucial role in increasing the tensile strength of the composite. The optical microstructural images of the composite show the adequate distribution of the reinforcing particles with the matrix. The proposed regression model shows better predictability of tensile strength. In addition, the methodology aids in optimizing the mixture component values to maximize the tensile strength of the produced functionally graded composite structure.Originality/valueLittle work has been reported so far where a hypereutectic Al–Si alloy is considered the matrix material to produce the composite structure. The article attempts to make a composite structure by using a combination of stir casting and centrifugal casting. Furthermore, it employs the mixture design to optimize the composition and predict the model of the study, which is one of a kind in the field of material science.

Fabrication and characterization of TiB2-reinforced functionally graded aluminum matrix material

2020 ◽  
Vol 72 (10) ◽  
pp. 1147-1152
Author(s):  
Ömer Savaş
Keyword(s):  
Wear Rate ◽  
Abrasive Wear ◽  
Peer Review ◽  
Centrifugal Force ◽  
Matrix Material ◽  
Aluminum Matrix ◽  
Functionally Graded ◽  
Aluminum Matrix Composites ◽  
Content Type

Purpose This study aims to investigate the production and abrasive wear rate of functionally graded TiB2/Al composites. TiB2 particles have been spontaneously formed in liquid matrix using in situ technique. The properties of composites such as hardness, abrasive wear rate and microstructure have been examined. Design/methodology/approach In situ TiB2 reinforcement phase was synthesized by using a liquid Al–Ti–B system. A semi-solid composite (Al(l)-TiB2(s)) prepared at 900°C was solidified under a centrifugal force to both grade functionally and give the final shape to materials. Abrasive wear test of materials was conducted using the pin-on-disk method at room temperature. The wear tests were carried out with two different loads of 1 Newton (N) and 2 N, a sliding velocity of 3.5 m s−1 and a sliding distance of 75 m. Findings This research provided the following findings; TiB2 particles can be successfully synthesized with in situ reaction technique in molten aluminum. It was determined that abrasive wear rate increases with increasing load and decreases with increasing TiB2 reinforcement content within matrix. Originality/value In previous studies, there have been many trials on the in situ production of TiB2-reinforced aluminum matrix composites. However, there are few studies on production of in situ TiB2-reinforced aluminum matrix functionally graded materials. At the same time, there is no study that the properties of composite, such as hardness and abrasive wear rate, are examined together according to centrifugal force. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0538/

Influence of loading conditions on wear behaviour of H11 tool steel

2019 ◽  
Vol 16 (5) ◽  
pp. 614-624 ◽  
Author(s):  
Sam Joshy ◽  
Jayadevan K.R. ◽  
Ramesh A. ◽  
Mahipal D.
Keyword(s):  
Plastic Deformation ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Tool Steel ◽  
Frictional Force ◽  
Normal Load ◽  
Hot Forging ◽  
Surface Hardness ◽  
Wear Behaviour ◽  
Content Type

Purpose In hot forging, a significant amount of forging force is used for overcoming frictional force at the die-billet interface. The high frictional force along with thermomechanical stress lead to wear, plastic deformation, mechanical fatigue and cracks, which reduce the service life of hot forging dies. Of all these different types of issues, wear is the predominant mode of failure in hot forging dies. This paper aims to describe mechanisms of wear transition in different loads at near forging temperature, occurring during sliding of chromium-based H11 tool steel specimens. Design/methodology/approach High temperature pin-on-disc tests are performed with pin specimens machined from bars of X38CrMoV5 steel, heat treated to surface hardness of 40-42 HRc. The disc is made of EN 31 steel with hardness of 60-62 HRc. Tests are performed at constant temperature of 500°C, and the normal load was varied from 20 to 70 N. Findings Scanning electron microscopy investigations on worn surface have revealed that wear is primarily due to abrasion and plastic deformation. The test results show an increasing trend in wear rate with increase in load up to 30 N, followed by a reversal in trend until 50 N. This transition in wear rate is caused by development of wear resistant layers, which are formed by compaction of wear debris particles on to the worn surfaces. These compact layers are found to be stable during load range from 40 and 50 N. However, with further increase in load, abrasive wear tracks are observed without any evidence of protective layers. As a result, there is an increase in wear rate with increase in loads above 50 N. In addition, plastic shearing was dominant over abrasive wear at this load regime. Originality/value The study on wear behaviour of H11 hot forging steel at 20 to 70 N will be an input to the research in hot forming industries.

In vitro comparison of the two hard-hard articulations for total hip replacements

2001 ◽  
Vol 215 (2) ◽  
pp. 153-160 ◽  
Author(s):  
C Rieker ◽  
R Konrad ◽  
R Schoun
Keyword(s):  
Wear Rate ◽  
Abrasive Wear ◽  
Experimental Methodology ◽  
Wear Behaviour ◽  
Linear Wear ◽  
Linear Wear Rate ◽  
Total Hip ◽  
Metal On Metal ◽  
In Vitro Comparison

Polyethylene particle disease is one of the major causes of late aseptic loosening of total hip replacement. Two hard-hard articulations (alumina-on-alumina and metal-on-metal) have been developed in Europe as an alternative to the ultra-high molecular weight polyethylene (UHMWPE) articulations. Even though these hard-hard articulations are on the market and numerous reports have been published about them, only a very limited number of studies allowing a direct in vitro comparison of the two articulations have been published so far. This paper compares in vitro these two types of articulation (alumina-on-alumina and metal-on-metal), which have been tested with a hip simulator for their tribological behaviour using exactly the same experimental methodology. This comparison shows that these two types of hard-hard articulation have very similar abrasive wear behaviour with four main features: 1. A running-in wear period (1 × 106 cycles) gives a cumulative wear of about 20 μm with head diameters of 28 mm. 2. After the running-in wear, there is a stabilization of the linear wear behaviour with a low linear wear rate/106 cycles for both types of articulation. 3. The volumetric wear rate of both articulations (<2.0 mm3/year for head diameters of 28mm) is significantly lower than that observed for metal-on-polyethylene or ceramic-on-polyethylene articulations having the same head diameter. 4. Abrasive wear is readily apparent (indicating a mixed lubrication regime) with both types of articulation. The extremely low wear performance of these articulations is confirmed and they constitute a lowwear alternative to the UHMWPE articulations currently used.

Thermal effects on mild wear transition in dry sliding of aluminium 7075-short glass fibre composites

2002 ◽  
Vol 216 (12) ◽  
pp. 975-982 ◽  
Author(s):  
S C Sharma ◽  
M Krishna ◽  
P S Vizhian ◽  
A Shashishankar
Keyword(s):  
High Temperature ◽  
Wear Rate ◽  
Glass Fibre ◽  
Operating Temperature ◽  
Wear Behaviour ◽  
Unreinforced Alloy ◽  
Wear Rates ◽  
Short Glass Fibre ◽  
Wear Transition ◽  
Short Glass

The unlubricated sliding high temperature wear behaviour of A17075 alloy composites reinforced with short E-glass fibre was evaluated. A17075-glass composites were prepared by the liquid metallurgical technique with 2, 4 and 6 per cent by weight. A high temperature sliding wear apparatus, with temperature range 30-200°C, was used to evaluate the wear rate. Results indicated that addition of short glass fibre to A17075 alloy not only delays the transition wear (transition between mild and severe wear) but also reduces the wear rate. However, in both unreinforced alloy and reinforced composites, the wear rates increased with increases in the load, operating temperature and sliding speed. Increase in the applied load and operating temperature increased the wear severity by changing the wear mechanism from adhesion wear to debris cracking induced delamination wear. The observations have been explained using scanning electron microscopy, X-ray diffraction and energy-dispersive spectroscopy analysis of the worn surfaces and the debris.

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