TiB2 Metal Matrix Composites Research Articles

Cold sprayed AlNiCoFeCr–TiB2 metal matrix composite coatings

In this work, the mechanically alloyed AlNiCoFeCr high entropy alloy (HEA) was used as matrix to develop metal matrix composite (MMC) coatings. Dense and thick AlNiCoFeCr – 30 wt % TiB2 MMC coatings were firstly fabricated by solid-state cold spraying (CS) technique at the low pressure of 0.9 MPa, and temperature of 300 and 450 °C. The effect of compressed air flow temperature and pressure parameters on structure and mechanical properties of coatings were established. As a low-temperature deposition process, CS completely retained the phase composition and nanostructure in the coatings without any phase transformation. With an increase in pressure up to 0.9 MPa a refinement of the coating structure and a double increase in the fraction of TiB2 particles in the coating were detected. An increase in temperature at least to 300 °C breaks down the oxide layers of the particles, multiplying the deposition efficiency and the properties of the coatings. The coatings fabricated at a spraying temperature of 450 °C and a compressed air flow pressure of 0.9 MPa exhibit the average thickness of 1110 μm, as well as a good combination of high microhardness (6.9 GPa) and sufficient indentation fracture toughness (3.8 MPa∙m1/2).

Process study for directed energy deposition of 316L stainless steel with TiB2 metal matrix composites

In addition to laser powder bed fusion, directed energy deposition (DED) is also gaining interest as an effective metal additive manufacturing technique. Due to its system configuration, it is more efficient and flexible for materials development. Therefore, it can be used for processing of metal matrix composites (MMCs) through the use of powder mixture as feedstock. 316L stainless steel has high corrosion resistance, biocompatibility, and ductility. Several studies have shown the feasibility of using DED to process 316L stainless steel. The material properties of 316L stainless steel can be improved using reinforcement particles such as TiB2 to form MMCs. In this study, the effects of process parameters on microstructure and mechanical properties of 316L stainless steel reinforced with TiB2 (316L/TiB2) MMC were studied. The process parameters, including laser power, scanning speed, and hopper speed, were varied and analyzed using Taguchi L9 array. It was found that the process parameters have insignificant effect on the bulk density of the samples produced. Through this study, it is also found that tumble mixing was not suitable for the powder feedstock preparation for MMCs to be processed by DED. The microstructure of DED 316L/TiB2 MMC samples consists of columnar and equiaxed grains. Columnar grains were located within the layers while equiaxed grains were located at the interlayer zones. Fine sub-grains were also observed within these grains and their boundaries were enriched with molybdenum and chromium segregations. Precipitates containing titanium were also observed to segregate at the sub-grain boundaries. Finally, the Vickers microhardness of the DED 316L/TiB2 MMC was found to be similar to pure 316L stainless steel produced by DED.

Investigation on mechanical properties and deformation behavior of copper-based three-phase metal matrix composite: Experimental and micro-macro-mechanical finite element analysis

The present study involved development of copper-based metal matrix composite, reinforced with waste EN 31 steel chips and TiB2 ceramic particles. Waste EN 31 steel chips and TiB2 ceramic particles were ball-milled for 100 h to obtain a single entity. The composite material was produced with a stir-casting technique, followed by a squeeze pressure process. The addition of Cu + 10 wt% of waste steel chips + 5 wt% of TiB2 improved the tensile strength of the copper matrix by about 68.35%. Furthermore, the addition of Cu + 5 wt% of waste steel chips + 10 wt% of TiB2 and Cu + 12.5 wt% of waste steel chips + 2.5 wt% of TiB2 increased the hardness and toughness of the copper matrix by about 133.33% and 28.57%, respectively. The addition of Cu + 10 wt% waste steel chips + 5 wt% of TiB2 ensured minimal corrosion weight loss in the metal matrix composite as a result of low porosity and a strong bond between the molecules. Further, representative volume element (size: 225 × 225 × 225 nm)-based finite element analysis was done to explain the micro-mechanical deformation, interfacial strength of matrix-particle interaction and damage behavior of Cu + 10 wt% of waste steel chips + 5 wt% of TiB2 metal matrix composite. A user material sub-routine model was also written and implemented with the help of FORTRAN subroutines to simulate the macro-mechanical tension test process of Cu + 10 wt% waste steel chips + 5 wt%TiB2 metal matrix composite. The results revealed a good agreement between the micro-mechanical and macro-mechanical finite element analysis models on the one hand and the experimental results on the other. Further, the representative volume element (with matrix and particles) showed about 59% and 66.5% higher tensile strength compared to the matrix–particle interface and the matrix (without particles), respectively. The percentage difference between the micro-mechanical finite element analysis and the experiments as well as the macro-mechanical finite element analysis and the experiments was found to be 5.58% and 9.64%, respectively. The finite element analysis results established that the waste steel chip powder particles exhibited greater stress than the TiB2 powder particles.

Effect of TiB2 addition on the microstructural, electrical, and mechanical behavior of Cu–TiB2 composites processed via spark plasma sintering

Abstract In this investigation, copper–TiB2 metal matrix composites were fabricated by spark plasma sintering. The effect of TiB2 (2.5, 5, 7.5, and 10 wt.%) additions on the microstructural, electrical, and mechanical properties of the composites was investigated. There was a remarkable reduction in processing time and temperature by this process as compared to conventional sintering. Scanning electron microscopy with energy dispersive X-ray spectroscopy elemental maps revealed a homogeneous distribution of TiB2 in the copper matrix. The hardness of the composites exhibited no consistent trend with the addition of TiB2. An improvement in tensile strength was observed at the expense of ductility. Electrical conductivity showed a decreasing trend. Morphology of the fracture surfaces was analyzed to predict the nature of failure under tensile load.

Investigation on Reinforcement Incorporation Factor and Microstructure of Al 7075/Submicron-TiB2 Metal Matrix Composites Processed through a Modified Liquid Metallurgy Technique

In this paper 0.8, 1.2, 1.6 and 2 wt.% of submicron-TiB2 particulate reinforced Al 7075 metal matrix composites (MMCs) were fabricated following a modified liquid metallurgy technique, which included ball milling, semi-solid stirring and ultrasonic agitation assisted squeeze casting method. Objective was to investigate their reinforcement incorporation factors (RIFs), microstructure through optical microscopy (OM) and scanning electron microscopy (SEM), and phase identification through X-ray diffraction (XRD) analysis. Phase distribution of different elements was analyzed through energy dispersive X-ray spectroscopy (EDS), and spatial distributions of elemental constituents were verified through elemental mapping. Mechanisms of TiB2 particulate dispersion and cluster segregation were highlighted. Results revealed excellent incorporation and dispersion uniformity of the reinforcements in the matrix phase. Squeeze casting process promoted the heterogeneous nucleation rate and rapid solidification, which resulted formation of Al-Zn-Mg-Cu based compounds in the dendritic regions. Occasional formation of reaction by-products (Al4C3) was observed at the interface of 1.2 wt.% TiB2 reinforced MMC. Reduction of precipitates and large grain refinements were observed for the MMC containing 1.6 wt.% of TiB2. In the microstructure of Al 7075/2 wt.% TiB2 MMC, superior dispersion of reinforcements at grain boundaries and inter-dendritic regions, along with presence of metastable η-MgZn2 phases was identified. Crystalline phase identification of all the composite samples was also performed through XRD analysis, which validated the elemental phase distribution results of EDS.

Regression analysis of hardness property of laser additive manufactured (LAM) Ti and TiB2 metal matrix composite

Abstract Additive manufacturing has gained relevance in aerospace components for intricate lattice, cooling channels, complex internal structure, and lightweight strong structures. Additive manufacturing has aided cost saving by reducing part count in expensive materials. Titanium di boride is a hard ceramic with a good oxidation stability with resistance to mechanical wear. It is a hexagonal crystal structured with a non-lustrous grey appearance. It has expressed a high value of strength to density ratio, melting point, and wear resistance. A predictive correlation and relationship between the optimal parameters and the hardness was examined. The data analysis of their relationship was examined in statistical analysis. A predictive mathematical formula was derived, and a linear and quadratic polynomial regression machine learning details of the factors showed correlation.

Analysis of wear properties and surface roughness of laser additive manufactured (LAM) Ti and TiB2 metal matrix composite

Abstract Industrial revolution in engineering materials applications through additive manufacturing has influenced the steel application in engineering industry. Limitations of wear of carbon steel has called for research focus in improving steel quality in wear resistance. Metallurgical applications of heat treatment were less effective as issues of temperature control; grain boundaries were evident. Matrix composite materials of better mechanical properties have been made use of to complement existing steel. This research focuses on the use of titanium, and titanium boride composite through laser cladding of addictive manufacturing. The admix composites were ‘mixed at different mass ratio, laser power and scan rate. A computer aided design (CAD) of design expert 9 was used to design the optimized parameters for the experimental analysis. Thirteen runs of random parameters of varying laser power and scanning speed were executed. An optimized laser power of 1500 W and scan rate of 1.2 m/min were derived and utilized. Nanocomposites of Titanium and Titanium di boride was at ratio loaded and cladded on steel rail surface. Metallurgical characterization of microscopic and macroscopic view was carried out. Different microstructural evolution was studied and analyzed. The wear tests were carried out at different loads of 2 N, 5 N and 10 N, respectively. The wear volume and wear rate were calculated. The least wear rate and wear volume was at the 50/50 mix ratio. A correlation and relationship between the wear properties, surface roughness and composition were examined.

A study on the mechanical and corrosion behaviour of bronze – TiB2 metal matrix composites

In the current scenario, there is a surge in the infusion of composite materials for a wider range of applications. Metal Matrix Composites offered numerous benefits regarding the enhancement of mechanical behaviour and also the corrosion behaviour under the influence of reinforcements. In this research, the bronze material, selected as the base material and TiB 2 , added as the reinforcement in different weight (wt) percentages (2%, 4%, and 6%). The liquid pathway (stir casting) is administered for composite preparation. This work focusses on the hardness, tensile strength and compressive strength of the prepared samples and also their corrosion behaviour. The presence of the reinforcements confirmed through XRD analysis and EDAX obtained with FESEM. Fractography studies are also conducted through FE-SEM. The results disclosed that the addition of reinforcement improves the mechanical characteristics of the composite samples. Corrosion properties indicated slight marginal improvement.

Investigation of Mechanical and Tribological Properties of Al6061–TiB2 Metal Matrix Composites

Abstract Aluminum alloys are commonly used in transportation, manufacturing, and related production fields for commercial applications because they possess high stiffness, strength-to-weight ratio, design flexibility, corrosion, and crack resistance. For this study, an attempt has been made to fabricate and improve the mechanical and sliding wear behavior of in situ–produced aluminum metal matrix composites (MMCs) with the titanium diboride (TiB2) particulate reinforcements by varying weight percentage from zero to six. The addition of TiB2 ceramic particle reinforcements to Al6061 matrix leads to an increase in material density and also results in a significant increase in modulus of the composite and specific strength as they have hardness of 86 HRA and high elastic modulus of 560 GPa. The Brinell hardness values of the composites along with the ultimate tensile strength (UTS) values were witnessed to increase with higher content of ceramic TiB2 because of uniform particle distribution and smaller size of filler at the lower elongation percentage. The microscopic investigations indicated that the change in hardness and UTS with increase in grain boundaries was due to fine interfacial bonding and coarse grain structure. Superior performance in properties was found at 6 wt. % of TiB2. The sliding wear tests were carried out at fixed velocity and at different loads. The wear test results of composites with TiB2 filler showed higher wear resistance because of effective load transfers at matrix ceramic particle interface.

Particle interspacing effects on the mechanical behavior of a Fe\u2013TiB2 metal matrix composite using FFT-based mesoscopic field dislocation mechanics

This paper presents an application to metal matrix composites (MMCs) of an enhanced elasto-viscoplastic Fast Fourier Transform (EVP-FFT) formulation coupled with a phenomenological continuum Mesoscale Field Dislocation Mechanics (MFDM) theory. Contrary to conventional crystal plasticity, which only accounts for plastic flow and hardening induced by statistically stored dislocations (SSDs), MFDM-EVP-FFT also describes the evolution of polarized geometrically necessary dislocation (GND) density and its effect on both plastic flow and hardening. Numerical results for a Fe–TiB2 MMC made of a ferrite matrix (α-Fe) and elastic ceramic particles (TiB2) are presented. Full-field simulations are performed using synthetic periodic unit cells representative of the MMC, with single-crystalline and polycrystalline matrix, for different particle interspacing distances. A strong dependence of the predicted equivalent stress, cumulated plastic strain and GND density fields with particle interspacing distance is observed, in contrast with conventional crystal plasticity. Correlations between these mechanical fields and microstructural features, and their influence on local and global mechanical behavior are examined for the different MMC microstructures.

Effect of in-situ sub-micron sized TiB2 reinforcement on microstructure and mechanical properties in ZE41 magnesium matrix composites

ZE41 Mg–TiB2 metal matrix composites with improved mechanical properties were synthesized via a novel processing route. In this process, the Ti–B system was developed without addition of third intermediate metallic Al powder, thereby preventing formation of any undesirable hazardous by-products from salt system (Al–K2TiF6–KBF4) and brittle TiAl3 intermetallic phase from master alloy (Al–Ti–B). Sub-micron sized TiB2 particles (5, 10 and 15 wt%) were reinforced in the ZE41-Mg alloy and the influence of TiB2 particles and its weight fraction on mechanical properties of composite materials were studied in details with an emphasis on microstructural characterization. The microstructural characterization shows reasonable uniform distribution of TiB2 particles in lower weight fraction of reinforcement and strong interfacial bonding with the matrix. A significant enhancement of the strength as well as grain refinement of composite were observed with increased TiB2 particles. The effect of TiB2 particle content on Young's modulus and yield strength was correlated via theoretical/mathematical modeling and experimental investigations. The strengthening mechanisms for strength enhancement of composites were established.

Corrosion behavior of stir-cast Al–TiB2 metal matrix composites

Abstract The present study evaluates the corrosion behavior of Al–TiB2 metal matrix composites in 3.5% NaCl solution. Composites are fabricated using stir-casting with varying wt.% of TiB2. Composite surfaces are characterized using scanning electron microscopy (SEM) images. Micro-hardness values of composites are obtained using a Vicker's micro-hardness tester. The hardness of the base matrix is enhanced due to the incorporation of hard TiB2 phase. Corrosion characteristics of composites are investigated using potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Corrosion resistance of composites is estimated from the parameters such as corrosion potential, corrosion current, linear polarization resistance etc. Corrosion resistance of the base alloy improves due to incorporation of TiB2 but only up to a certain amount of TiB2 phase in the matrix. The composite with 1 wt.% TiB2 shows the highest corrosion resistance. Corroded surfaces are studied using SEM images that reveal localized pitting corrosion on composite surfaces.

Particle-induced damage in Fe–TiB2 high stiffness metal matrix composite steels

Fe–TiB2 metal matrix composites, termed high modulus steels, have great potential for lightweight design applications due to their high stiffness/density ratio. However, the observed embrittlement, caused by the TiB2 particles, critically limits application of these steels. Experimental studies to identify the influence of particle microstructure on ductility and toughness are complex in view of the multitude of parameters affecting microstructural damage. We therefore pursue instead an integrated computational materials engineering approach to gain understanding and derive guidelines for optimizing the particle microstructure and thus improve the mechanical properties, particularly the damage tolerance of these high modulus steels. Key microstructural parameters such as particle clustering degree, size and volume fraction were investigated. Model geometries were statistically and systematically generated with varied particle configurations from random to clustered distributions. Simulations were performed using a crystal plasticity Fast Fourier transformation method coupled with a novel phase field damage model. The influence of particle configuration on damage initiation and evolution was evaluated from the simulation results, and it was observed that microstructures with homogeneous particle distributions of 7 to 15 vol% TiB2, devoid of large TiB2 particles stemming from primary solidification, appear most favorable for obtaining high modulus steels with optimized mechanical properties.

Corrosion Characterization of Aluminium 6061 Tib2 Metal Matrix Composites in Sodium Hydroxide Medium

Corrosion Characterization of Aluminium 6061 Tib2 Metal Matrix Composites in Sodium Hydroxide Medium

Dry Sliding Wear Behaviour Of AA6082-5%SiC AND AA6082-5%TiB2 Metal Matrix Composites

In the present work, dry sliding wear behavior of AA6082-5%SiC and AA6082-5%TiB2 metal matrix composites processed through the stir casting method was studied. Using Design of experiment software, the experiments were planned and conducted at 10–50N applied load and 200–1400 rpm rotational speed. The wear behavior was studied for metal matrix composites which are prepared according to specific dimensions using a pin- on- disc tribometer at room temperature. Process parameters: Applied load and rotational speed are considered to study the effect on the wear are plotted. It is observed that the effect of process parameters on mass loss on both the composites was found to be different. Optical microscopy studies reveal the presence of both adhesive and abrasive wear mechanisms due to the hard SiC and TiB2 reinforcement particles.

Study on three-body abrasive wear behavior of functionally graded Al/TiB2 composite using response surface methodology

ABSTRACTFunctionally graded LM13 Al/10 wt% TiB2 metal matrix composite has successfully produced under centrifugal casting. Hollow cylindrical composite with dimensions 150 × 150 × 15 mm was produced under rotating centrifugal speed of 1100 rpm. Microstructural characteristics were studied on the composite surfaces at distance of 1, 5.5, and 10 mm from outer periphery of the casting, and the results revealed that surface at distance of 1 mm has presence of more reinforcement particles. An objective of this study was to characterize abrasion wear behavior at the composite surfaces using dry abrasion tester. Mathematical models were developed using response surface methodology to study the relationship of parameters such as load, speed, and distance from outer periphery with abrasion wear rate. Face centered Central Composite Design with 20 experiments was preferred for dry abrasion test. Adequacy of model was predicted through analysis of variance, and the significance test result shows that load has major impact on the wear rate. The optimized parametric condition to obtain minimum wear rate was found as load of 33 N, speed of 112 rpm, and distance of 1 mm from outer periphery. Scanning electron microscopy analysis done at worn out surface showed maximum wear resistance at the outer periphery.

Effect of pouring temperature on A356-TiB2 MMCs cast in sand and permanent moulds by in-situ method

AbstractThe paper describes a different condition of pouring temperature by sand and permanent mould to produce A356-6 wt% TiB2 metal matrix composites by in-situ method salt metal reaction route. The observation of SEM micrographs shows particle distribution of the TiB2 and it appears in hexagonal shape in Al matrix. The results of X-ray diffraction (XRD) analysis confirmed the formation of those TiB2 particulates and the results showed TiB2 particles are homogeneously dispersed throughout the matrix metal. Subsequent structure-property evaluation studies indicated sub-micron size reinforcement of in-situ formed TiB2 particles with improved physical and mechanical properties as compared to sand and permanent mould of Al-TiB2 composites. From, the permanent mould Al-TiB2 composite has an advantage of increase the properties over sand mould Al-TiB2 composite.

Development of Novel Al-Alloy (Al-5Mg)/10Wt.%TiB<sub>2</sub> Metal Matrix Composites by <i>In Situ</i> Reaction Synthesis

The present paper describes a cost effective route to produce Al alloy-10 wt % TiB2 metal matrix composites by in-situ molten flux assisted reaction synthesis. Now a days main focus is given to aluminium alloy as a matrix material due to its unique combination of good corrosion resistance, low density, superior mechanical properties, good vibration damping, higher wear resistance due to which alloy finds extensive applications in naval applications. With TiB2 as particulate addition in Al-Alloy (Al-5Mg) matrix properties of alloy can greatly be improved.

Corrosion and Wear Properties of Composite Coatings Reinforced with Particles Produced by PTA on Steel Substrate in Different Atmospheres

Titanium diboride (TiB2) and titanium carbonitride (Ti(C,N)) coatings are widely used as reinforcing materials in applications demanding high corrosion and wear resistance. In this paper, plain carbon steel has been surface alloyed with TiB2 by plasma transferred arc (PTA) technique using two different gas atmospheres. The first metal matrix composite (MMC) is produced with TiB2 particles and argon as shielding and plasma gas. In addition, a mixture of Ar and 5% N2 was used as shielding and plasma gas for producing of second MMC coating. The microstructure of both alloyed layers consists of primary titanium boride particles surrounded by a eutectic matrix, containing ferrite, eutectic boride, and titanium carbonitrides. The presence of these carbonitrides is more intense in the case of the N-enriched alloyed layer, as it was also proved via X-ray Diffraction. The alloyed layers are susceptible to pitting corrosion in 3.5% NaCl or 1 N H2SO4. The alloyed layer produced with nitrogen mixture gas is slightly more noble than the one produced with pure Ar. The metallic-ferritic matrix corrodes in 6% FeCl3∗6H2O leaving TiB2 particles protruding from the matrix. The wear performance of both TiB2 MMC depends on the counterbody (tool steel or alumina ball).

A Comparative Study on the Microstructures and Mechanical Properties of Al 6061 Alloy and the MMC Al 6061/TiB<sub>2</sub>/12<sub>p</sub>

Al 6061 alloy is widely used for commercial applications in the transportation, construction and similar engineering industries. It possesses excellent mechanical properties in addition to good corrosion resistance due to which the alloy finds extensive application in naval vessels manufacturing. Al-TiB2 composite is a metal matrix composite (MMC) that can be manufactured using the in-situ salt-metal reaction. With TiB2 as the particulate addition the properties of Al 6061 alloy can be greatly improved. A comparison of the mechanical properties and the microstructure of Al 6061 alloy with Al–TiB2 metal matrix composite containing 12% by weight TiB2p manufactured through the in-situ process was presented.