Internal Friction Behavior Research Articles

Phase transition and internal friction behaviors in Mn-doped Co-V-Ga shape memory alloys

Shape memory alloys with a high abundance of mobile interfaces exhibit remarkable internal friction (IF) behaviors, which can be utilized for the reduction of noise and vibration. In this study, we systematically investigate the martensitic transformation and internal friction behaviors in the Mn-doped Co53V35–xGa12Mnx (x = 0 - 10) polycrystalline alloys. Our findings indicate that using Mn to replace V results in decreased transformation temperatures but increased thermal hysteresis. The addition of Mn enhances magnetic exchange interaction, leading to a gradual enhancement in magnetization difference across martensitic transformation, thereby compromising the transformation entropy change and arresting the martensitic transformation. At a frequency of 0.4 Hz, the intensity of transformation IF peak is enhanced from 0.124 to 0.178 with increasing the Mn content from 0 to 4.5 %, as a result of deteriorated geometrical compatibility between austenite and martensite due to the addition of Mn. Furthermore, hydrogenation treatments substantially improve both the peak intensity and frequency dependence of peak position for the relaxation-type IF, demonstrating the great contribution from hydrogen-twin boundary interaction.

Microstructure regulation and internal friction behavior of Fe45Mn20Cr15Co20 duplex high-entropy damping alloy

Damping alloys not only have the physical property of converting mechanical vibration energy into heat energy and dissipating it but also have good mechanical properties, corrosion resistance, structural stability, and so on. In this paper, a Fe45Mn20Cr15Co20 high-entropy alloy was prepared by vacuum arc melting, and the effects of annealing temperature on the evolution of its structure and internal friction behavior were investigated in depth. The results show that the annealing treatment improves the alloy’s damping performance significantly. The best damping performance was obtained after annealing at 1000 °C: Q−1max= 0.0729, an increase of 22.5% compared with the as-cast state. Combining mechanical and damping properties, the alloy is annealed at 1000 °C to obtain the best combined strength-damping properties. Thus, the design requirement of structural-functional integration is achieved. In addition, the alloy still maintains the two-phase structure of γ austenite and ε martensite after annealing treatment, and the content of ε martensite phase increases gradually with the increase of annealing temperature. The alloys formed a regular arrangement of chevrons and annealed twins when annealed at 1000 °C. The magnetic properties of the alloys gradually increase with the annealing temperature. The tensile strength of the annealed alloy tends to increase and then decrease with the increase of annealing temperature and reaches a peak (Rm = 780.8 MPa) at 1000 °C. This paper provides a reference of experimental data for realizing structural-functional integration of high entropy damping alloys.

Microstructure and Internal Friction Behavior of Laser 3D Printed Fe-Based Amorphous Composites

Microstructure and Internal Friction Behavior of Laser 3D Printed Fe-Based Amorphous Composites

Microstructural Evolution and Internal Friction Behavior of a Ferrite/Martensitic Steel Induced By Equal-Channel Angular Pressing

Microstructural Evolution and Internal Friction Behavior of a Ferrite/Martensitic Steel Induced By Equal-Channel Angular Pressing

Twinning damping interface design and synergistic internal friction behavior in FeMnCrCo high-entropy alloys

Vibration and noise reduction has always been important problem to be solved in the fields of rail transit, aerospace, marine engineering, and so on. In this paper, a novel Fe65-XMn20Cr15CoX (X = 5, 10, 15, 20) dual-phase high-entropy damping alloy with excellent properties were prepared by vacuum melting. The dependence of the alloy damping behavior on the twin interface, magnetic properties and phase interface was emphatically analysed. The effects of Co content on its microstructure, damping behavior and magnetic properties were investigated. The results show that with the increase of Co content, ε martensite gradually transforms to γ austenite, and the number of twins increases gradually. The peak damping (Q−1) increased from 0.0442 to 0.0595, an increase of 34.6%. The coupled effects of magneto-mechanical hysteresis, twin interface motion, and phase interface motion provide the alloy's excellent damping properties. The alloy has a higher damping internal friction peak of around 200 °C, which is due to the phase transition from ε to γ at the temperature. By adjusting the Co content, the phase content and twinning and other microstructures of the alloy can be regulated, and multiple damping mechanisms can be coupled to achieve higher damping performance.

Effects of Nb addition and heat treatment on the microstructure, mechanical property and internal friction behavior of FeCrAlMo cladding alloys

FeCrAl based alloy was a good candidate as an accident tolerant fuel (ATF) cladding material, this research investigated the influence of Nb addition and heat treatment on the evolution of dispersed Fe2Nb precipitates, the mechanical property and Internal Friction (IF) behavior of Nb containing Fe-13Cr-4.5Al-2Mo alloys. Fe-13Cr-4.5Al-2Mo-1.5Nb (wt%) annealed at 1000 °C exhibited the highest ultimate tensile strength (UTS) and an acceptable ductility at each tested temperature (room temperature, 300 °C, 500 °C or 800 °C). For example, the UTS of FeCrAlMo-1.5 wt% Nb at 800 °C was 95 MPa, 73% higher than that of Nb-free FeCrAlMo alloy at the same test temperature. Comparing with IF results of the cold-rolled Nb-free FeCrAlMo alloy in the first heating cycle, a high IF peak (∼P2) located at about 680 °C disappeared in the Nb containing FeCrAlMo alloy. Based on the optical micrographs analysis, the reason may be the pinning effect by the high density nanoscale Fe2Nb particles on dislocations, P2 peak would be expected to find at higher temperature; Likewise, the disappearance of P3 in the Nb containing FeCrAlMo alloys proved the pinning effect of Fe2Nb particles on grain boundaries. Based on the IF theory and microstructure characterization, the disappearance of P2 (recrystallization peak) and P3 (grain boundary peak) in the Nb containing FeCrAlMo alloys well proved that this pinning effect by high density Fe2Nb nanoscale particles was the main reason for improving the tensile strength of the Nb containing FeCrAlMo alloys.

Influence of Rheological Properties of Lithium Greases on Operating Behavior in Oscillating Rolling Bearings at a Small Swivel Angle

In this study, the behavior of greases during oscillating bearing operation with a small oscillation angle and high frequency was investigated. This mode of operation entails demands on the lubrication system that differ significantly from those for continuously rotating bearings. In order to determine the variables influencing the suitability of a lubricating grease for small angle oscillating operation, the grease samples were examined with particular regard to their rheological properties. The focus of this investigation was to find a relationship between the rheological parameters and the real behavior in the bearing. Therefore, rheological and physical parameters, which influence the long-term structural changes and lubrication conditions, were identified. For this purpose, the viscosity was measured over a wide shear-rate range. The storage and loss modulus, the work of deformation, and the adhesion force jump are also determined. Afterward, rotational transient flow measurements were performed. These allowed us to analyze the development of the shear stress over time, at a constant shear rate, and to examine the internal friction behavior by evaluating the energy density. Subsequently, grease-lubricated four-point bearings were used in component tests, while the frictional torque was measured. These bearings operated in oscillating motion. Moreover, the yield point of mechanically aged greases was measured and compared with that of fresh greases to examine the influence of the oscillating operation on the lubricant condition. Finally, correlations between grease composition, rheological measurements, and component tests were investigated. Thereby, parameters influencing the frictional behavior of greases in rolling bearings during oscillating operation at small swivel angles were identified.

Comparison of internal friction measurements on Ni-Ti reinforced smart composites prepared by additive manufacturing

Polymer 3D printing has been utilised in aerospace to produce complex lightweight structures, in medical fields to print tissues and organs, and in a number of other industries to combat the rising demand for weight-saving engineering solutions. Pure polymer goods created through 3D printing, on the other hand, lack strength and functionality. Therefore, by combining matrix and reinforcing materials, 3D printing of polymer composites can overcome these problems. Also various researchers have used matrix system either epoxy resin or vinyl ester resin. Despite its wide usage, resins have few drawbacks like microleakage and high curing time which could be eliminated by 3D printing. In this work, we have focused on using 3D printed polymer matrix system. To enhance the property, shape memory alloys (SMAs) are introduced in the structure as a reinforcement. Shape memory alloys are a class of smart material that, when heated over a certain temperature, can recover deformation. SMAs exhibit two main characteristics i.e., shape memory effect (SME) and superelasticity (SE). SMAs are available in a variety of shapes, including wires, springs, sheets, and tubes. The SMA wires can be embedded in the composites for a variety of reasons, such as enhancing mechanical properties, shape morphing of structures and for use as actuators. Damping is one such mechanical property which can enhanced by reinforcing SMA wires. In this research work, the samples were fabricated using 3D printing of PLA and PETG with SMA wires embedded in two different forms i.e., continuous and discontinuous. The samples were then examined under a dynamic mechanical analyzer to study the damping (internal friction) behaviour of the smart composites. It has been found that the incorporation of SMA wires into the matrix had a significant influence on the dynamic mechanical properties. Also, the samples with SMA reinforced in continuous manner had the higher value of tan δ i.e., it had good damping properties in comparison to short fibre reinforced composites.

Effect of substitutional Ni atoms on the Snoek relaxation in ferrite and martensite Fe-C alloys: An atomisitic investigation

Quantitative simulations of the carbon-induced internal friction in ferrite/martensite Fe-C and Fe-Ni-C alloys are performed by combining a mean-field elastic model and the atomistic kinetic Monte Carlo based on a pair interaction model to describe the composition-dependent carbon migration. The simulation is validated by experimental data and a thermo-kinetic theory. Our results predict that (i) additional peaks occur in the internal friction profiles of Fe-C and Fe-Ni-C due to C-C and Ni-C pair interactions; (ii) the Ni-alloying shifts the internal friction peak to lower temperature than in Fe-C alloys; (iii) the peak temperature is not simply related to the most frequent carbon jumps during the relaxation process; (iv) the internal friction behavior in martensite depends on the excitation direction with respect to the carbon ordering direction.

Effects of thermal shock on the microstructure, mechanical and thermophysical properties of ZrC-C composites

To explore the effects of thermal shock cycles on ZrC-C composites, their microstructure, coefficient of thermal expansion (CTE), compressive strength and internal friction behavior after different thermal shock cycles were studied. As the thermal shock cycle between 1500 ℃ and room temperature increased from 0 to 30, the CTE of the ZrC-C composites with the ZrC/PyC (Pyrolytic carbon) weight ratio of 1.7 first increased and then decreased, and its compressive strength increased by 35.8 % (295.4 ± 10.1 MPa) after 10 thermal shock cycles and could still be maintained above 85 % of its original strength after 30 thermal shock cycles. The changed interface bonding strength between ZrC skeleton and PyC resulted in the first decrease and then increase of their internal friction. This work provides an effective strategy for optimizing the thermal shock resistance of ultra-high temperature composites by regulating the component contents.

Wet Drilled Cuttings Bed Rheology

The cuttings transport efficiency of various drilling fluids has been studied in several approaches. This is an important aspect, since hole cleaning is often a bottleneck in well construction. The studies so far have targeted the drilling fluid cuttings’ transport capability through experiments, simulations or field data. Observed differences in the efficiency due to changes in the drilling fluid properties and compositions have been reported but not always fully understood. In this study, the cuttings bed, wetted with a single drilling fluid, was evaluated. The experiments were performed with parallel plates in an Anton Paar Physica 301 rheometer. The results showed systematic differences in the internal friction behaviors between tests of beds with oil-based and beds with water-based fluids. The observations indicated that cutting beds wetted with a polymeric water-based fluid released clusters of particles when external forces overcame the bonding forces and the beds started to break up. Similarly, it was observed that an oil-based fluid wetted bed allowed particles to break free as single particles. These findings may explain the observed differences in previous cutting transport studies.

The Influences of Third Alloying Element on the Internal Friction Behavior and the Mechanical Properties in the Water Quenched Ti-12Mo Alloys

The influences of third alloying element on the internal friction behavior and the mechanical properties in the water quenched Ti-12Mo alloys were investigated using multifunctional internal friction apparatus and mechanical testing machine, respectively. The two relaxational internal friction peaks that are named as P1 and P2 peaks were found in the water quenched Ti-12Mo alloys. Third alloying element has influences on the P1 and P2 peaks. In addition, the young modulus and yield strength are also influenced by the addition of Third alloying element.

Internal friction of Ni-Al intermetallic compound formation in sintering process

The Ni-Al intermetallic compounds, as important high-temperature structural materials, have clear target requirements in a number of fields. Powder metallurgy is an important candidate for preparing the Ni-Al intermetallic compounds. Clarifying the formation and transformation process of Ni-Al intermetallic compounds in sintering process and determining the solid diffusion reaction temperature and types of intermetallic compounds are greatly important for tailoring sintering process and optimizing product quality. In this paper, the internal friction behaviors of Ni-Al powder mixture compacts in the sintering process are systematically investigated by the internal friction technique. A typical internal friction peak is observed in the internal friction-temperature spectrum. The peak height decreases with the measuring frequency increasing, but the peak temperature is independent of frequency. Moreover, the internal friction peak shifts toward higher temperature and the peak height increases as the heating rate increases. It is reasonable that the internal friction peak belongs to the typical phase transformation internal friction peak which is associated with the formation of intermetallic compounds NiAl<sub>3</sub> and Ni<sub>2</sub>Al<sub>3</sub> in the heating process. Furthermore, the microstructure of the Ni-Al powder mixture can be tailored by mechanical ball-milling. The internal friction peak shifts toward lower temperature and the peak height decreases with the ball-milling time increasing, which indicates that the solid diffusion reaction can be activated at lower temperature with a slower reaction rate. This decrease is related to the refinement of powder particles, the lamellar formation of powder mixture, the enhancement of solid solution degree and surface energy, and the shortened atomic diffusion distance due to the mechanical ball-milling. It is also indicated that the mechanical ball-milling can effectively reduce the initial temperature of solid diffusion reaction, thus lowering sintering temperature.

Internal friction behavior of Zr59Fe18Al10Ni10Nb3 metallic glass under different aging temperatures

We investigate the role of aging temperature on relaxation of internal friction in Zr59Fe18Al10Ni10Nb3 metallic glass. For this purpose, dynamic mechanical analysis with different annealing temperatures and frequency values is applied. The results indicate that the aging process leads to decrease in the dissipated energy in the temperature range of glass transition. It is also found that the increase in applied frequency weakens the loss factor intensity in the metallic glass. Moreover, the Kohlrausch–Williams–Watts (KWW) equation is used to evaluate the evolution of internal friction during the aging process. According to the results, higher annealing temperature will make the primary internal friction in the material increase; however, a sharp decline is observed with the time. The drop in characteristic time of internal friction is also closely correlated to the rate of atomic rearrangement under the dynamic excitation so that at higher annealing temperatures, the driving force for the collaborative movement of atoms is easily provided and the mean relaxation time significantly decreases.

On Glass Forming Ability of Bulk Metallic Glasses by Relating the Internal Friction Peak Value

The internal friction (IF) behaviors of a series of LaCe-, Zr-, and La-based bulk metallic glasses (BMGs) were studied by a computer-controlled, conventional inverted torsion pendulum. The results indicate that with an increasing temperature, the IF also increases gradually in the supercooled liquid region, followed by a decrease caused by crystallization. BMGs with a good glass forming ability (GFA) usually possess a high IF peak value for an alloy system with the same constituent elements. Furthermore, the magnitude of the IF value (Qi−1) of the inflection point is an efficient criterion of GFA. The Qi−1 value is a valid criterion under the conditions of identical constituent elements and different element contents. However, Qi−1 and GFA have no relationship among different alloy systems.

Digital Image Correlation Based Internal Friction Characterization in Granular Materials

Based on the realization that Newtonian fluids have the unique property to redirect the forces applied to them in a perpendicular direction, a new apparatus, called the Granular Friction Analyzer (GFA), and the related GFA index, were proposed for characterizing the internal friction and related flow behavior of granular materials under uniaxial compression loading. The calculation of the GFA index is based on the integration of the internal pressure distribution along the cylinder wall, within which the granular material is being uniaxially compressed by a piston. In this paper an optical granular friction analyzer (O-GFA) is presented, where a digital image correlation (DIC) method is utilized to assess the cylinder strains used to calculate the internal pressure distribution. The main advantage of using the DIC method is that the starting point (piston–powder contact point) and the length of the integration considering the edge effects can be defined. By using the DIC full-field, instead of a few points strain measurements, a 2% improvement of the GFA index’s accuracy has been achieved and its robustness with respect to the number of points has been demonstrated. Using the parametric error analysis it has been shown that most of the observed total error (7.5%) arises from the DIC-method-based measurements of the strains, which can be improved by higher-resolution cameras and DIC algorithms for the strain evaluation. Additionally, it was shown that the GFA index can be used for determining the well-known Janssen model parameters. The latter was demonstrated experimentally, by testing three SS 316 L granular material samples with different mean particle sizes. The results confirm that the mean particle size regulates the internal friction of granular materials.

Internal Friction Behavior Associated with Martensitic Decomposition in Low-carbon Dual-phase Steel

Internal Friction Behavior Associated with Martensitic Decomposition in Low-carbon Dual-phase Steel

Effect of La addition on high-temperature order-disorder phase transformation in Fe − 18Ga alloy

The microstructure, internal friction (IF) behavior spectra, heat flow curves, and mechanical strength of Fe-18Ga-xLa (x = 0.05, 0.1, 0.2, 0.5, and 1.0 at.%) alloys were systematically analyzed in this investigation. In the IF spectra, a relaxation IF peak (Labeled as P1) and a peak related to order-disorder phase transition (Labeled as Ptr) are observed in the temperature range of 400 °C–690 °C. It is found trace La doping has a significant effect on the Ptr peak. With the increase of the La-doped content, the peak of Ptr gradually shifts to a lower temperature and the net peak height decreases. Combining with phase diagram, DSC, Grazing Incidence X-ray diffraction (GI-XRD) spectra and SEM, the mechanisms of the reduction of both the critical temperature and the strength of Ptr peak for the Fe-18Ga-xLa alloy are ascribed to the precipitation of LaGa2 phase, which reduces the Ga content gradually in the matrix. Further, the mechanism is verified in Fe-18.1Ga alloy and Fe-19.3Ga alloy. In addition, the trace La doping can significantly improve the mechanical strength of the Fe − 18Ga alloy.

Effects of thermal shock on the microstructures, mechanical and thermophysical properties of SiCnws-C/C composites

In order to understand the effects of thermal shock cycles between 1100 °C and room temperature on SiC nanowires reinforced carbon/carbon (SiCnws-C/C) composites, their microstructure, internal friction behavior, coefficient of thermal expansion (CTE), flexural strength and fracture morphology before and after different thermal shock cycles were studied. The results show that the fiber/matrix (F/M) interface debonding and matrix cracks are the main reasons for the increase of porosity. The SiCnws-C/C composites has the largest internal friction in the whole testing frequency after 10 thermal cycles. The CTE of the composites first decreases and then increases to some extent with the increase of the thermal cycles. The flexural strength of SiCnws-C/C composites increases by 23% after 10 thermal cycles, and then reduces to 92% of the original strength after 20 thermal cycles. The increase of flexural strength and internal friction after 10 thermal cycles is associated with the appropriate F/M interface weakening and the increased d002 values, which also results in the decrease of CTE. Compared to C/C composites, the better thermal shock resistance of SiCnws-C/C composites is attributed to the nanoscale strengthening mechanism brought by SiC nanowires, including their pull-out and bridging.

Snoek-type relaxation caused by interstitial atoms in sintered <i>β</i>-type Ti-Nb alloy

<sec> The <i>β</i>-type Ti-Nb alloys are potential shape memory and superelasticity materials. The interstitial atoms in the alloys have important effect on their physical and mechanical properties. For the interstitial atoms, the internal friction technique can be used to detect their distributions and status in the alloys. The influences of chemical compositions and heat treatments on the microstructures of the containing-oxygen Ti-Nb alloys are given, and a clear understanding and the relaxational mechanism of the internal friction peak correlated with oxygen are also clearly discussed by investigating the internal friction behavior of the alloys and the detecting their microstructures. </sec><sec> The Ti-Nb alloys with different Nb content values are prepared by powder metallurgy. The internal friction behaviors of Ti-Nb alloys with different Nb content values and heat treatments are investigated by using dynamic mechanical analysis (dynamic mechanical analyzer, DMA) Q800 from TA Instruments in single cantilever mode under different testing parameters and conditions from room temperature to 350 ℃. The X-ray diffraction experiments are also carried out in order to detect the differences among the microstructures of the specimens with different heat treatments for the Ti-35.4Nb alloy. It is shown that relaxational internal friction peaks are found on the internal friction temperature dependent curves of the sintered and water-quenched alloys. The internal friction peak is correlated with Nb content. The peak does not appear in the sintered Ti-Nb alloys with low Nb content. The maximum of the internal friction peak appears in the quenched alloy with about 35% Nb. The internal friction peak height increases monotonically with Nb content increasing in the present testing composition range for the sintered alloys. The relaxation parameters are the activation energy <i>H<sub>wq</sub></i> = (1.67 ± 0.1) eV and the preexponential factor <i>τ</i><sub>o<i>wq</i></sub> = 1.1 × 10<sup>－17 ± 1</sup> s for the quenched Ti-35.4Nb alloy . In addition, the peak height also depends on heat treatment. The water-quenched Ti-35.4Nb alloy has much higher internal friction peak than the as-sintered alloy with identical compositions. The internal friction peak height is also correlated with the quenching temperature. It is found that the peak is linked to the <i>β</i> phase of Ti-Nb alloys and that the peak height is determined by the stability and amount of the <i>β</i> phase from their microstructures. When the stability of the <i>β</i> phase decreases, the peak height increases, and the increase in the amount of <i>β</i> phase results in the increase of the peak height. The <i>β</i> phase in the quenched Ti-35.4Nb specimen is metastable <i>β</i> phase (<i>β</i><sub>M</sub>), which can be transformed into the stable <i>α</i> and <i>β</i><sub>S</sub> by ageing. The <i>β</i> phase in as-sintered specimen is the stable <i>β</i> phase (<i>β</i><sub>S</sub>). The modifications of microstructures of the specimens with different heat treatments result in the difference in peak height between the water-quenched and as-sintered Ti-35.4Nb specimens. That the peak height presents a maximum in the vicinity of 35 wt.% Nb for the quenched alloys results from the variation of the stability and amount of <i>β</i><sub>M</sub> with Nb content. That the height of the peak increases monotonically with Nb content increasing in as-sintered alloys is attributed to the increase of the amount of <i>β</i><sub>S</sub>. It is suggested that the internal friction peak is related to oxygen jump in lattice or the interaction between the oxygen-substitute atoms in <i>β</i><sub>M</sub> phase for the water-quenched alloys and those in <i>β</i><sub>S</sub> phase for the as-sintered alloys.</sec>