NiAl Matrix Composites Research Articles

Fabrication and assessment of dry sliding behavior of Ti3C2Tx-MXene reinforced nickel aluminide composites

MXene has been recognized globally for its ability to act as a solid lubricant, lubricant additive, and protective coating for enhancing the performance and longevity of dynamics systems. Ni3Al matrix composites have been fabricated through spark plasma sintering with varying Ti3C2Tx-MXene concentrations and slid against the Si3N4 ball to evaluate the lubrication potential at atmospheric conditions. The addition of MXene in the matrix has improved anti-friction and anti-wear properties attributed to the formation of a tribo-layer on encountering surfaces consisting of oxides and MXene’s fragments, as confirmed by TEM and Raman spectroscopy. However, further increasing MXene to 20 % led to an increase in friction, ascribed to the dominance of the hard TiC phase, which acts as a barrier for tribo-layer formation.

Fabrication and wear behavior of TiC/TiB2-reinforced NiAl intermetallic matrix composites

Combustion synthesis (CS) is a well-known technique for manufacturing intermetallic compounds and intermetallic-matrix composite materials. This research focuses on fabricating NiAl-matrix composites with varying TiC/TiB2 contents as reinforcement, achieved by the combustion synthesis method. The chemical reactions that yield the final NiAl–TiC–TiB2 compounds were interpreted using thermodynamic calculations. The phase analysis and morphology of the composites were investigated using X-ray diffractometry (XRD) and scanning electron microscopy (SEM) characterization techniques, respectively. The findings demonstrate that the NiAl matrix contains evenly distributed TiC–TiB2 ceramic-based particles, and no oxidation of reactants occurred during the combustion reaction. With an increase in the TiC–TiB2 reinforcement phases from 0 to 15 wt %, the hardness of the NiAl–TiC–TiB2 product significantly rose from 496 to 1015 Vickers, while the porosity increased from 24% to 39%, attributed to the reduced quantity of melted NiAl available to fill the pores. Examining tribological behavior in synthesized composites involved combining experimental-numerical methods, utilizing sliding wear tests and artificial neural network (ANN) modeling. The wear results revealed decreasing wear rates with reduced loads (from 35 N to 25, and 15 N) and higher TiC/TiB2 ceramic content. Iron traces at C0 and C10 worn samples were 2.47 and 26.18 wt % respectively, which indicates enhanced hardness. The experimental data were used to train and test an artificial neural network (ANN) and statistical analysis revealed a remarkable accuracy of 91% for the ANN model in predicting friction coefficients within SHS-processed composites, as indicated by the R2 value of 0.91 and a MAPE of 6.47.

Tribological Behavior and Self-Healing Properties of Ni3Al Matrix Self-Lubricating Composites Containing Sn-Ag-Cu and Ti3SiC2 from 20 to 800 °C

As a high-temperature structural material, Ni3Al matrix composites are often used to manufacture basic mechanical components that need to be used in high-temperature conditions. To meet the increasing demand for metal matrix composites with an excellent tribological performance over a wide temperature range, Ni3Al matrix self-lubricating composites containing Sn-Ag-Cu and Ti3SiC2 (NST) were synthesized via laser-melting deposition. Dry sliding friction tests of NST against Si3N4 ball were undertaken from 20 to 800 °C to investigate the tribological behavior and wear-triggered self-healing properties. The results show that the tribological behaviors of NST are strongly dependent on the testing temperature and self-healing properties. At low and moderate temperatures from 20 to 400 °C, as the Sn-Ag-Cu flows into the cracks and is oxidized during sliding friction, while the cracks on the worn surface are filled with oxides consisting mainly of Al2O3, SnO2 and CuO. At higher temperatures of 600 and 800 °C, the cracks are filled by the principal oxides of Al2O3, TiO2 and SiO2 due to the partial decomposition and oxidation of Ti3SiC2. Compared with other testing temperatures, the recovery ratio relative to the Ni3Al base alloy of the cracks on the worn surface of NST is the highest at 400 °C, which is about 76.4%. The synergistic action mechanisms of Sn-Ag-Cu and Ti3SiC2 on the crack self-healing from 20 to 800 °C play a significant role in forming a stable solid lubricating film, improving the anti-friction and wear resistance of NST. The results provide a solution allowing for metal matrix composites to achieve excellent lubrication stability over a wide temperature range by virtue of the crack self-healing properties.

The microstructure characteristics and self-lubrication mechanism of the NiAl matrix composites prepared by vacuum hot-pressing sintering

NiAl–Ti3AlC2 and NiAl–Mo2TiAlC2 composites were fabricated in-situ using a vacuum hot-pressing sintering technique. The microstructure and high temperature tribological performance of the composites were studied. When compared with NiAl–Ti3AlC2 composite, the NiAl–Mo2TiAlC2 composite contained the Mo2TiAlC2 precipitated phases and some nano-precipitated phases of Mo2TiAlC2 distributed along the grain boundaries. Meanwhile, the high temperature tribological property of NiAl–Mo2TiAlC2 composite was more superior than that of NiAl–Ti3AlC2 composite. The worn surface of NiAl–Mo2TiAlC2 composite formed a dense and continuous lubricating layer of MoO3 when subjected to the friction test at 800 °C, which could effectively improve the overall tribological properties of the composites.

Microstructure, Tribological Behavior, and Strengthening Mechanisms of the Friction Interface Layer with Nanocrystalline Structure of Ni3Al Matrix Self-lubricating Composites

This work investigated the microstructure, tribological behavior and strengthening mechanisms of friction interface layer with nanocrystalline structure of graphene-reinforced Ni3Al matrix composites (GNMCs) synthesized using laser melting deposition. A dislocation density-based model was selected to analyze the mechanisms of the improvement in the wear resistance of the friction interface layer from initial wear stage to stable wear stage. Results show that GNMCs exhibit excellent antifriction and wear resistance in the stable wear stage due to the formation of friction interface layer with nanocrystalline structure. Grain boundary strengthening is the predominant strengthening mechanism of friction interface layer of GNMCs. Dislocations are blocked at grain boundaries to form complex dislocation barriers, further contributing to the high strength and wear resistance. The dislocation density-based model can be successfully used to predict the mechanical response of the friction interface layer subjected to the grain refinement during sliding friction process.

In-situ TiB2–NiAl composites synthesised by arc melting: oxidation behaviour, oxidation kinetics and oxidation mechanism

ABSTRACT Endogenetic particles TiB2 (5 and 10 vol.-%)-reinforced NiAl matrix composites were fabricated in-situ from Ti–B–Ni–Al system by arc melting. The oxidation behaviour and anti-oxidant mechanism of TiB2–NiAl composite were investigated at 1173 K in air atmosphere. The composite had a rapid rate of oxidation during the first 20 h. With the increase in oxidation time, α-Al2O3 oxidation films and needle-shaped TiO2 phases were formed on the surface of the composite. As the Al oxidised into Al2O3, the NiAl phase transformed into γ-Ni3Al phase. The oxides were beneficial for improving the oxidation resistance of the composite. The mass change of the composite was less than 2.5 mg cm−2 after being oxidised at 1173 K in air atmosphere for 100 h. The composite showed excellent high-temperature oxidation resistance.

Microstructure, mechanical and tribological properties of NiAl matrix composites with addition of BaO/TiO2 binary oxides

BaO and TiO2 reacted and produced BaTiO3 in the process of sintering. As a result, the diffraction peaks of BaTiO3 became stronger with the increasing BaO/TiO2 contents. The diffraction peaks of NiAl shifted smaller angle to left with the addition of BaO/TiO2. Meanwhile, the lattice distortion obviously occurred in the composite structure. The composites with the addition of BaO/TiO2 presented high microhardness and yield strength as well. The composite with 20% BaO/TiO2 had the highest microhardness value and yield strength of 474.5 HV and 2786 MPa, respectively. The friction coefficient and wear rate of the composites decreased with the addition of BaO/TiO2 and the NiAl-30% BaO/TiO2 composite had the lowest friction coefficient at 800 °C test temperature. The BaTiO3 was decomposed to BaO and TiO2 during high temperature sliding.

Microstructure and Mechanical Properties of Ni3Al Matrix Composites with Fine Aluminum Oxide by PM Method

Microstructure and Mechanical Properties of Ni3Al Matrix Composites with Fine Aluminum Oxide by PM Method

Effects of Cr3C2 content and temperature on sliding friction and wear behaviors of Cr3C2/Ni3Al composite materials

Chromium carbide (Cr3C2)-reinforced Ni3Al matrix composites, which possess excellent high-temperature strength and wear resistance, are considered as potential high-temperature wear-resistant materials. In this study, effects of Cr3C2 content on the friction and wear properties of Cr3C2/Ni3Al composites and their counterpart gray cast iron disks were investigated at different temperatures. The worn surface morphologies of the Cr3C2/Ni3Al composites and gray cast iron disks were analyzed to understand their wear mechanisms. The analysis results showed that in the Ni3Al matrix composites, a combination of abrasive wear and adhesive wear occurred at room temperature, whereas adhesive wear was severer at 200 °C. Furthermore, the optimum Cr3C2 contents of the Cr3C2/Ni3Al composites were found to be 18 vol% and 12 vol% at room temperature and 200 °C, respectively. The volume loss of the composites increased with an increase in the fraction of the Cr3C2 strengthening phase at 350 °C. The wear resistance of the gray cast iron disks decreased with an increase in temperature. In contrast, the wear resistance of the Ni3Al matrix composites increased with an increase in temperature. This increased wear resistance of the composites is attributed to the transformation of their wear mechanism with increasing temperature.

Tribological performance of Ti3SiC2 enhanced Ni3Al matrix composites

The dry sliding tribological tests of Ni3Al matrix composites with various contents of Ti3SiC2 against Si3N4 ceramic balls are carried out under 10 N–0.6 m s−1 for 30 min at 25 °C. The morphologies and compositions of worn surfaces and wear debris are systematically characterized to explore the wear mechanisms. The results indicate that different contents of Ti3SiC2 have a great influence on their tribological properties. Among all specimens, Ni3Al matrix composite containing 10 wt% Ti3SiC2 has the excellent tribological properties, whose friction coefficient and wear rate are 0.59 and 3 × 10−5 mm3N−1m−1 respectively. The excellent tribological performance can be attributed to the formation of a lubricating film consisting of an amorphous mixture of Ti and Si oxides.

Tribological Performance of Ni3Al Matrix Composites Synthesized by Laser Melt Deposition Under Different Scanning Velocities

In order to study the effect of scanning velocity on the microstructure and tribological properties of Ni3Al matrix composites containing graphene nanoplatelets (NGs), a series of NG samples are successfully synthesized by laser melt deposition under the various scanning velocities from 300 to 500 mm s−1. The sliding friction tests of NG against GCr15 steel balls are carried out under 10 N and 0.2 m s−1 at room temperature. The microstructures, tribological properties and wear mechanisms of the NG samples are analyzed. The results show that the scanning velocity can be optimized to effectively control the surface hardness and relative density, as well as tribological performance of NG. The NG sample synthesized under scanning velocity of 450 mm s−1 has a dense and fine microstructure as well as excellent properties such as higher relative density (98.6%), lower friction coefficient (0.23) and wear rate (5.5 × 10−6 mm3 N−1 m−1). The lower substrate layer with dense and stable structure plays an important role in supporting the upper glaze layer with rich graphene and oxides, as well as nanocrystalline structure, which contributes to the excellent friction-reducing and wear resistance performances of NG. The research results could be used to guide the selection of suitable scanning velocity and study the wear mechanisms of NG for having excellent tribological performance.

In-situ TiB2-NiAl composites synthesized by arc melting: Chemical reaction, microstructure and mechanical strength

TiB2 particles (5 vol% and 10 vol%) reinforced NiAl matrix composites were fabricated in-situ from Ti-B-Ni-Al system by arc melting. The reaction mechanism and mechanical properties of the composites were studied. When the reaction system was heated to 917 K, Ni and Al reacted with Ti to form the transient phase AlNi2Ti, which continued to react with B to yield ultrafine TiB2 particles acting as reinforcement agent. The apparent activation energy for these two reactions were calculated and found to be 497.99 kJ/mol and 2354.78 kJ/mol, respectively. The reinforcement agent exerted dispersion strengthening effect on the matrix. The room temperature compressive strength of the composites reinforced by 10 vol% of TiB2 particles was determined to be 538.3 MPa, representing a 35.2% increase over NiAl alloy. To further refine the grain size, the rare earth element cerium (2 wt% and 4 wt%) was introduced to the composites. The compressive strength of the composites containing 4 wt% Ce was determined to be 571.1 MPa, representing a 43.5% increase over NiAl alloy.

Tribological Performance of Ni3Al Matrix Self-Lubricating Composites Containing Multilayer Graphene Prepared by Additive Manufacturing

In order to improve tribological performance of Ni3Al-based alloy, Ni3Al matrix composites containing 1.5 wt.% multilayer graphene (MLG) are prepared through additive manufacturing (AM) and spark plasma sintering (SPS), which are denoted as NMAM and NMSPS, respectively. Tribological behaviors of NMAM and NMSPS against Si3N4 balls are researched under constant speed (0.2 m/s) and varied loads (from 4 to 16 N) for evaluating the tribological properties of NMAM and NMSPS. The results present that NMAM exhibits the excellent tribological properties [low friction coefficients (0.26-0.40) and considerable wear resistance (2.8-4.6 × 10−5 mm3 N−1 m−1)] as compared to NMSPS, which attributes to the uniform enrichment of MLG with properties of high tensile strength and being easily sheared off on the worn surfaces. Owing to the use of spherical prealloyed powder containing multilayer graphene and the characteristics of layer by layer depositing in the AM process, NMAM has a more compact and uniform substrate, which persistently provides a source of the formation of continuous and stable frictional layer. Due to the characteristics of AM rapid solidification, NMAM has the small grain size and well-compacted microstructure, which can effectively reduce the probability of spalling wear and lead to the increase in wear resistance of materials. The research can offer the reference for self-lubricating materials prepared by AM technology.

Tribological Properties of NiAl Matrix Composites Filled with Serpentine Powders

The unexplored tribological properties of NiAl matrix composites filled with serpentine powders are investigated using a reciprocating ball-on-disk configuration. Tribological test results reveal that increasing the serpentine concentration to some extent reduces the friction coefficients and wear rates of the composites. The best anti-friction and anti-wear performance is displayed by the NiAl matrix composite filled with 8 wt.% serpentine and 2 wt.% TiC (NAST). Microstructural analyses demonstrate that after adding serpentine, the self-lubricating films with different percentages of coverage form on the worn surfaces of the composites. A self-lubricating film with the highest percentage of coverage smears on the worn surface of NAST. This clearly suggests that serpentine can act as a new type of filler for NiAl matrix composites, whereas a combination of serpentine and TiC can enable serpentine to provide a full play to its excellent lubricating performance.

Tribological Performance of Ni3Al Matrix Self-Lubricating Composites Containing Multilayer Graphene and Ti3SiC2 at Elevated Temperatures

The application of Ni3Al-based alloy (NA) in the field of aerospace was limited by its poor tribological properties. For improving the tribological performance of NA, multilayer graphene (MLG) and Ti3SiC2 were added in Ni3Al matrix composites. Tribological behavior of Ni3Al matrix composites containing 1.5 wt.% MLG and 10 wt.% Ti3SiC2 (NMT) against Si3N4 ball at 12 N-0.2 m/s from 25 to 750 °C was investigated. The results showed that NMT exhibited the excellent tribological behavior [lower friction coefficients (0.26-0.57) and less wear resistance (3.1-6.5 × 10−6 mm3 N−1 m−1)] due to synergetic effect of MLG and Ti3SiC2 over a wide temperature range from 25 to 750 °C. At 25-350 °C, part of MLG enriched on worn surface could play a role in reducing friction and improving wear resistance. At 350-550 °C, although MLG gradually lost the lubricating properties, the partial decomposition of Ti3SiC2 could continually improve the tribological properties of NMT. At 550-750 °C, Ti3SiC2 on worn surface was oxidized to form lubricating film, while Ti3SiC2 in the subsurface played an important role in supporting the film, resulting in the excellent high-temperature tribological performance. The research had good guiding significance for the preparation of wide temperature range self-lubricating material and the study of synergetic effect of complex solid lubricants.

Tribological performance of Ni3Al matrix composites with MoO3 tabular crystal under different sliding speed

In order to study the tribological performance of Ni3Al matrix composites containing MoO3 tabular crystals (Ni3Al-MTCs) under different sliding speed, the friction and wear behaviors of Ni3Al-MTCs sliding against Si3N4 ball are tested using a constant load of 10 N at room temperature under 0.1–0.7 m/s. The effects of shear stress and different amount of friction heat on the wear mechanism of Ni3Al-MTCs under different sliding speed are studied. The results show that MoO3 tabular crystals are beneficial to the formation of friction layer with the increase of sliding speed, resulting in the excellent tribological properties of Ni3Al-MTCs. At 10N-0.7 m/s, higher friction heat at higher speed produces rich oxides on worn surface, which is beneficial to the formation of smoother and larger coverage of lubricating film with good antifriction property. In addition, lower shear stress acting on worn surface at higher speed brings the more stable friction layer with excellent wear resistant property, if compared to other working conditions. The results could be used to guide the selection of suitable working conditions and study the wear mechanisms of Ni3Al-MTCs for having excellent tribological performance during sliding process.

Effect of Hardness Ratio on the Wear Performance and Subsurface Evolution of Ni3Al Matrix Composites

ABSTRACTA favorable hardness ratio (Hdisk/Hpin = Hd/Hp) could lead to a transition to mild wear during sliding contact. To determine a more appropriate Hd/Hp value for the sliding wear, the dry sliding pin-on-disk wear tests of Ni3Al matrix composites (NMCs) with multilayer graphene (MLG) are undertaken at Hd/Hp values of 0.99, 0.83, 0.42, and 0.35 at sliding speeds of 0.1, 0.3, 0.5, and 0.7 m/s. It is found that the tribological properties of NMCs are strongly affected by the various hardness ratios. At 0.1 m/s, the friction coefficient decreases with a decrease in Hd/Hp value. The low friction coefficient is 0.14 and the wear rate is 0.9 × 10−5 mm3 N−1m−1 under the ceramic counterpart with Hd/Hp of 0.35. At 0.7 m/s, the tribological properties show the opposite trend with a decrease in Hd/Hp. At an Hd/Hp of 0.35, the smooth compact layer on the worn surface could decrease the friction at 0.1 m/s, and the improved hardness in the subsurface by strain hardening would play an important role in the improvement of wear resistance. Under the metal counterpart with Hd/Hp of 0.99, plastic deformation only occurs on the contact surface and the MLG could suppress further shear deformation in the subsurface, leading to a low wear rate (2.4 × 10−5 mm3 N−1m−1) and friction coefficient (0.15) at 0.7 m/s.

Study on Tribological Performance of NiAl Matrix Self-Lubricating Composites Containing Graphene at Different Loads

ABSTRACTThis study aimed to explore the possibility of improving the tribological performance of NiAl matrix composites by graphene addition. Friction and wear experiments of as-prepared specimens were conducted under different conditions using a pin-on-disk wear testing machine. NiAl matrix composites containing graphene showed satisfactory performance in friction coefficient and wear resistance compared to NiAl matrix composites without graphene. For the active effect of graphene, the friction coefficient and wear rate of NiAl matrix composites were maintained at relatively lower values. The beneficial antifriction and antiwear effects of graphene gradually failed when the applied load was above 8 N. Graphene in NiAl matrix composites played an active role in the formation of a friction layer, which was beneficial to the lower friction coefficient and wear rate. In light of this research, graphene plays an active role in reducing the friction coefficient and wear rate. Hence, graphene has great potential in applications as an effective solid lubricant to promote tribological behavior.

Microstructure and Functional Mechanism of Friction Layer in Ni3Al Matrix Composites with Graphene Nanoplatelets

Microstructure and functional mechanism of friction layer need to be further researched. In the present work, the friction coefficients and wear rates are analyzed through response surface methodology to obtain an empirical model for the best response. Fitting results show that the tribological performance of Ni3Al matrix composites (NMCs) with graphene nanoplatelets (GNPs) is better than that of NMCs without GNPs, especially at high sliding velocities and high loads. Further research suggests that the formation of integrated friction layer, which consists of a soft microfilm on a hard coating, is the major reason to cause the differences. Of which, the wear debris layer (WDL) with a low shear strength can reduce the shear force. The ultrafine layer (UL), which is much harder and finer, can effectively avoid fracture and improve the load support capacity. Moreover, the GNPs in WDL and UL can be easily sheared and help to withstand the loads, trending to be parallel to the direction of shear force.

High Temperature Lubricating Behavior of NiAl Matrix Composites With Addition of CuO

High temperature self-lubricating NiAl matrix composites with addition of CuO (15, 20, and 25 wt.%) were fabricated by powder metallurgy technique, and the tribological behavior from room temperature to 1000 °C was investigated. It was found that Ni–Cu and Al2O3 phases formed during the fabrication process due to reaction of NiAl and CuO. The tribological results showed that the composite with addition of 25 wt.% CuO has a favorable friction coefficient of about 0.2 and excellent wear resistance with the magnitude of 10−6 mm3 N−1 m−1 at high temperatures (800 and 1000 °C).