Plastic Strength Research Articles

Unraveling microstructure evolution induced mechanical responses in coaxial fiber-diode laser hybrid welded Fe–36Ni Invar alloy

Invar alloys, renowned for its ultra-low coefficient of thermal expansion, are qualified for widespread use in aerospace applications. This study explores the utilization of fiber-diode laser hybrid welding in Fe–36Ni Invar alloy, specifically focusing on addressing the undesirable microstructure and properties arising from unstable molten pool and high-temperature gradient encountered during single fiber laser welding. Experimental and simulation analyses were conducted to systematically explore the influence of diode laser power on the microstructure evolution and mechanical responses of fiber-diode hybrid laser welded Invar alloy joints. Results indicate that the addition of diode laser could notably widen the keyhole opening and improve the molten pool stability. An acceleration of dynamic recrystallization is observed in the weld seam, with a significant increase in high-angle grain boundaries, which account for over 90 % of the total. Moreover, with increasing diode laser power, temperature gradient decreases, leading to the formation of numerous equiaxed grains. Electron backscatter diffraction (EBSD) results demonstrate a considerable enhancement in the intensity of the γ texture, particularly the {111}<110> texture. Comparatively, fiber-diode laser hybrid welding exhibits superior plasticity and tensile strength over single fiber laser welding, with a tensile strength reaching 493.1 MPa. The research findings presented here provide essential theoretical foundations and technical guidance for enhancing the quality of Invar alloy weld joints and facilitating the broader application of fiber-diode laser hybrid welding in the future.

Effect of synergistic microalloying on the microstructural optimization of Mo/NiAl alloy with excellent mechanical properties under rapid non-equilibrium solidification

Low room-temperature plasticity and poor high-temperature strength extremely restrain the extensive application of NiAl composites. Herein, our work synergistically optimized the NiAl microstructure via alloying of Mo to relieve imbalance of strength and ductility under rapid non-equilibrium solidification supplemented with the first principle calculation. Remarkably, the addition of Mo significantly refined the microstructure of NiAl–15Mo. Moreover, enhanced by the uniform precipitation Mo phase, the coordinately deformed Mo phase at the grain boundary and the partial Mo solid solution occupied Ni sites, the NiAl–15Mo showed superior strength-ductility. The mechanical properties (σ0.2, σUCS, UT) of NiAl–15Mo composites at room temperature were 944 MPa, 1841 MPa, and 27,068 MPa·%, which were increased by ∼55.3 %, ∼48.7 % and ∼41.0 % compared with the conventional NiAl composites, respectively. In particular, owing to solid-solution Mo atoms restrict the climb of dislocations and the stronger covalent bond orbital hybridization between Ni-3d and Mo-4d, the mechanical properties (σ0.2, σUCS, UT) of NiAl–15Mo at 1000 °C are 212 MPa, 265 MPa and 7922 MPa·%, which has an increase of ∼175.3 %, ∼120.8 % and ∼228.0 %, respectively. This work provides a new perspective to manipulate and coordinate Mo multiple reinforcing ways and achieve the high strength and plasticity of NiAl composites.

Mg-Sc-Nd-xZn series alloys with medium strength and high plasticity

Different application scenarios put forward diverse requirements of mechanical properties for magnesium alloys. In this study, the extruded Mg-Sc-Nd-Zn alloy series with high plasticity and medium strength was developed. The uniformly distributed Mg3Nd (β1) phase, high-density twins, and the activated non-basal dislocation slips contribute to the high plasticity of Mg-Sc-Nd alloy. With the addition of Zn element, the appearance of coarse ScZn phases, which prevents the activation of {101¯ 2} tensile twins, leads to an increase in strength but a simultaneous decrease in the plasticity of the extruded alloys. Adjusting the Zn content in the Mg-Sc-Nd-xZn allows a series of alloys with various strengths and plasticity matching. The results obtained in this work are of great importance for developing a regulatable magnesium alloy series that aims at different application scenarios.

Magnetic Hyperporous Elastic Material with Excellent Fatigue Resistance and Oil Retention for Oil-Water Separation.

Oily wastewater has caused serious threats to the environment; thus, high-performance absorbing materials for effective oil-water separation technology have attracted increasing attention. Herein, we develop a magnetic, hydrophobic, and lipophilic hyperporous elastic material (HEM) templated by high internal phase emulsions (HIPE), in which free-radical polymerization of butyl acrylate (BA) and divinylbenzene (DVB) is employed in the presence of poly(dimethylsiloxane) (PDMS), lecithin surfactant, and modified Fe3O4 nanoparticles. The adoption of the emulsion template with nanoparticles as both stabilizers and cross-linkers endows the HEM with biomimetic hierarchical open-cell micropores and elastic cross-linked networks, generating an oil absorbent with outstanding mechanical stability. Compressive fatigue resistance of the HEM is demonstrated to endure 2000 mechanical cycles without plastic deformation or strength degradation. By exploiting the synergistic effect of hierarchical structures and low-surface-energy components, the resulting HEM also possesses excellent and robust hydrophobicity (water contact angle of 164°) and good oil absorption capacity, in which Fe3O4 nanoparticles lead to convenient magnetically controlled oil recyclability as well. Notably, the unique biomimetic microporous structure demonstrates superior oil retention capacity (>95% at 1000 rpm and >60% at 10,000 rpm) over the state-of-the-art porous materials for a diverse variety of oils to reduce the risk of secondary oil leakage, along with good recoverability by squeezing owing to the excellent compression resilience. These excellent performances of our HEM provide broad prospects for practical applications in oil-water separation, energy conversion, and smart soft robotics.

A novel NbTaV0.5Hf0.1 complex concentrated alloy with superior room-temperature tensile plasticity and elevated-temperature strength

Refractory complex concentrated alloys (RCCAs) encounter difficulties in balancing room-temperature ductility and high-temperature strength, which restricts their applications. Here, a novel NbTaV0.5Hf0.1 RCCA was prepared through vacuum arc melting for the first time. The as-cast alloy exhibited a stable body-centered cubic phase structure with a small amount of micro-scale dispersed Hf-rich oxides. As a result, the designed alloy exhibits a room-temperature tensile fracture strain of 14.9 %, and superior compressive yield strength values under elevated temperatures (472 MPa under 1200 ℃, 358 MPa under 1400 ℃, respectively). A synergy between room-temperature tensile ductility and exceptional high-temperature strength was achieved in RCCAs.

Improvement of Geotechnical Properties of Clayey Soil Using Biopolymer and Ferrochromium Slag Additives.

The geotechnical properties of clay soil and its mixtures with different proportions (0.75%, 0.85%, 1%, and 1.15%) of Agar Gum biopolymer and Ferrochromium Slag (0.25%, 0.50%, 0.75%, and 1%), having various curing times and freeze-thaw cycles, were studied through a series of soil mechanical tests to investigate possibilities to improve its undesired/problematic plasticity, compaction, and shear strength characteristics. The results revealed that treatment with an optimal ratio of 1% Agar Gum and 1% Ferrochromium Slag alone, as well as together with, improved the geotechnical properties of the clay soil considerably. Both the unconfined and shear strength properties, along with the cohesion and internal friction angle, increased as much as 47 to 173%, depending on the curing time. The higher the curing time, the higher the shear strength, cohesion, and internal friction angle are up to 21 days. Deteriorating the soil structure and/or fabric, freeze-thaw cycles, however, seem to have an adverse effect on the strength. The higher the freeze-thaw cycle, the lower the shear strength, cohesion, and internal friction angle. Also, some improvements in the plasticity and compaction properties were determined, and environmental concerns regarding Ferrochromium Slag usage have been addressed.

The Effect of Carboxymethyl Cellulose (CMC) Addition on The Quality of Biodegradable Plastic from Corn Cob

This study aims to determine the effect of CMC addition on thickness, tensile strength, elongation and biodegradation of biodegradable plastic from corn cob starch. In this study, the addition of Carboxymethyl Cellulose which plays a role in increasing the tensile strength of biodegradable plastics. This research was conducted in 2 stages. The first stage is varying CMC as much as 20%, 30%, 40%, 50% and 60% (w/b starch) and the second stage is mixing corn cob starch as much as 2 grams with CMC 20% - 60% w/b starch. The test results showed that the addition of CMC concentration of 20% w/w with corn cob starch mixing material had an effect on increasing the tensile strength value and decreasing the elongation value of the plastic. The addition of CMC concentration as much as 20%-60% w/b starch with corn cob starch blending material has an effect on increasing the percent weight loss of biodegradable plastics

Karakteristik Arang Kulit Buah Kakao dan Arang Batang Bambu Terhadap Mutu Briket

The purpose of this research is to determine the optimum properties of biodegradable plastic made from banana weevil starch with the addition of straw cellulose as reinforcement. This research was conducted using Completely Randomized Method (CRD) with four treatments and four replications. In this study were the addition of straw cellulose with a ratio of starch and cellulose 1:0; 1:0,5 ; 1:1 and 1:1,5. Tests were carried out on strong tensile strength, elongation at break, biodegradation, swelling and water vapor transmission rate. The data obtained were analyzed statistically using analysis of variance (ANOVA). The addition of straw cellulose had a significant effect on the manufacture of biodegradable plastics. The result were biodegradable plastic increase tensile strength, decreases elongation at break, increase biodegradation and air resistance, reduces the rate of water vapor transmission. Biodegradable plastic with the best treatment is the ratio of starch starch ratio of 1 : 1.5 cellulose. The best result biodegrabable plastic has for tensile strength value of 9.56 MPa, elongation 6.8%, complete biodegradation on day 6, swelling 41.51% and WVTR 0.0156%.

Strength and Compressibility Characteristics of An Expansive Soil with addition of GGBS and Alkali Activated Slag

Abstract: The phenomenal development in civil engineering infrastructure in developing countries like India, soil stabilization has emerged as à key problem in the engineering industry. Engineers have been attempting to enhance the engineering properties of low-quality soil due to their negative impact on project performance. With increasing awareness of environmental issues, there has been a remarkable shift towards green and sustainable technologies. Reuse of waste materials have been advocated for quite a while to improve the properties of poor soils open up to new avenue and double advantage of waste management. In the project investigation an attempt to evacuate the Plasticity characteristics, Strength characteristics and Compressibility characteristics were conducted on selected soil as per Indian Standards using GGBS and Alkali Activated Solution (AAS) with different percentages and curing for 0,3,7,14, and 28 days to analyze the variation of engineering properties. From the results combination of (GGBS + AAS) proved to increase of strength and reduce compressibility characteristics. The combination of GGBS + AAS is cost effective, non-destructive, low energy demanding and ecofriendly than GGBS to the selected expansive soil.

Innovative plasticization technique for talc-powder reinforced wheat-starch biomass composite plastics with enhanced mechanical strength

N-methyl-morpholine-N-oxide (NMMO) was initially created as a plasticizer for starch to produce thermoplastic wheat starch. Subsequently, talc powder was used as a reinforcing filler to enhance the mechanical strength of thermoplastic biomass-based composite plastics. The chemical structure, crystal structure, and microscopic morphology were analyzed using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Additionally, the thermal properties were explored through thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The hydrated NMMO plasticizer demonstrated an outstanding plasticizing effect on starch, resulting in a composite with remarkable mechanical properties. In fact, the pure thermoplastic wheat starch plasticized with hydrated NMMO exhibited the highest mechanical strength recorded so far, with a tensile strength of up to 9.4 MPa. In addition, talcum powder displayed a noticeable reinforcing effect. When the talcum powder content reached 30 wt%, the targeted composite achieved a tensile strength of 20.5 MPa and a Young's modulus of 177.9 MPa. These values were 118 % and 48 % higher, respectively, than those of the pure thermoplastic starch sample. This innovative plasticizing method opens up a new avenue for the development of high-mechanical-strength thermoplastic biomass-based composite plastics with promising potential applications.

Multiscale analysis of traditional and non-traditional additive amended expansive soil-A comparative evaluation

The expansive soils have always been complex and problematic for construction purposes and challenging for the geotechnical fraternity. However, structural alterations and chemical stabilization methods have been practiced successfully in many practical applications. These soils interact with the chemical additives based on the chemical composition, curing period and quantity. The stabilization methods have also focused on non-traditional, eco-friendly additives, which can be a suitable alternative to conventional alkaline additives. However, extensive experimentation is required at various testing levels to understand the stabilization mechanism and the longevity of the additives in the soil medium. The present study uses lime, a conventional additive and a non-traditional additive-lignosulphonate (LS), to stabilize the expansive soil. The interaction mechanism of soil and the additives is investigated at macroscale and microscale levels to understand the modifications rendered to the virgin soil. The effect of the additives in terms of quantity and curing period is studied with respect to plasticity characteristics, strength development and microstructural modifications. The interaction behaviour of soil and the additive is compared at each level, and a probable interaction mechanism is proposed for both additives from this study. The criticality of lime amendment depends on the curing effect and the quantity. A strength improvement factor of 9 and 2 is observed for lime and LS amendment. The compressive/tensile strength ratio is higher for lime amendment, indicating excessive brittleness compared to LS. The conventional additives contribute to higher strength and brittleness, as opposed to lower strength gain and less brittleness of non-conventional additives.

SPATIAL VARIABILITY OF SOIL PHYSICAL PROPERTIES IN SOUTHERN MANKAYAN, BENGUET, PHILIPPINES

Abstract. Hydrothermal alteration in the Mankayan Mineral District in Benguet, Philippines, has had a significant impact on the soil characteristics. Thus, soil characterisation in landslide zones offer useful insights on the nature of slope failure and provide baseline data that may be used with susceptibility mapping and hazard zonations. The study elucidated the physical characteristics of the soils in the southern portion of Mankayan and mapped out the spatial distribution in the area. High sand and low clay content cause low slope stability due to the low water retention in soil, low plasticity, and low shear strength of materials while the resulting porosity led to poor drainage. Results show that the soil's physical properties, whereas most rock units have been affected by alteration, have caused rock deterioration that eventually led to slope failures. The presence of various parent material in the study site influenced the distribution of soil physical properties, specifically the influence of dacite on the Atterberg limits in the central area of southern Mankayan.

ВИЗНАЧЕННЯ ОПТИМАЛЬНОЇ ТЕМПЕРАТУРИ ЗАГАРТУВАННЯ ЕКОНОМНОЛЕГОВАНОЇ КОНСТРУКЦІЙНОЇ СТАЛІ ПРИ РЕАЛІЗАЦІЇ ПРОЦЕСУ Q та P

The work presents practical experience of applying mathematical modeling of the multiphase structural state of low-alloy structural steel 0.30С–0.86Si–1.02Mn–0.84Сr in order to obtain improved indicators of strength and plasticity of the metal. Calculated theoretical optimum quenching completion temperature when implementing the Q&amp;P (Quenching and Partitioning) process for the specified steel. It is shown that the optimal temperature of the completion of the quenching process should be 245 °C, when "fresh" (secondary) martensite is not formed during the final cooling, and the fraction of residual austenite reaches a maximum (approximately 27 % vol.). Austenite stabilization is known to be important in Q&amp;P treated steels to achieve the desired combination of strength and plasticity. The obtained results will be used to develop effective modes of strengthening heat treatment of metal products of responsible purpose with the provision of increased indicators of plasticity and impact strength at ambient temperature.

Hydrogen Embrittlement of 27Cr-4Mo-2Ni Super Ferritic Stainless Steel.

The effect of hydrogen content on the deformation and fracture behavior of 27Cr-4Mo-2Ni super ferritic stainless steel (SFSS) was investigated in this study. It was shown that the plasticity and yield strength of SFSS were very susceptible to hydrogen content. The introduction of hydrogen led to a significant decrease in elongation and a concurrent increase in yield strength. Nevertheless, a critical threshold was identified in the elongation reduction, after which the elongation remained approximately constant even with more hydrogen introduced, while the yield strength exhibited a monotonic increase with increasing hydrogen content within the experimental range, attributed to the pinning effect of the hydrogen Cottrell atmosphere on dislocations. Furthermore, the hydrogen-charged SFSS shows an apparent drop in flow stress after upper yielding and a reduced work hardening rate during the subsequent plastic deformation. The more hydrogen is charged, the more the flow stress drops, and the lower the work hardening rate becomes.

In-situ induce reinforcement in WAAM of Al-matrix composite using active N2 as shielding gas followed by friction stir processing

Economic and active nitrogen (N2) is used as a shielding gas for the wire-arc additive manufacturing (WAAM) of Al-matrix composite (AMC). Although no crack was found, large flaky nitrides up to 500 μm are generated in the matrix of the Al alloy, leading to a significant deterioration in both plasticity (reduced by 81.4%) and tensile strength (reduced by 17.5%) compared with the deposit protected by argon (Ar), which is to be modified. Then, FSP was performed on the matrix of the Al alloy. The influence of friction stir processing (FSP) on the microstructure and mechanical properties in the stirred zone (SZ) of WAAM 5356 Al alloy deposit, prepared under a N2 environment, was studied. Flaky nitrides were observed in the Al matrix, and were broken due to FSP. The large flaky nitrides with a length of 500 μm were broken into granular nitrides with sizes lower than 2 μm. The grain size in the SZ decreased by 83% after FSP, and the microhardness in the SZ became more uniform, with an average value of 91.9 HV. Owing to the refinement of AlN by FSP, the tensile strength and elongation of the AMC were 349 MPa and 19.9%, much more than that before FSP of 231 MPa and 5.5%, showing an increase of 51.1% and 261.8%, respectively. The plasticity has obvious improvement, which is higher than the common used stir casting AMC.

Study of the effect of combined reinforcement and modification of epoxy resin with rubbers on the impact strength of carbon fiber-reinforced plastic

Study of the effect of combined reinforcement and modification of epoxy resin with rubbers on the impact strength of carbon fiber-reinforced plastic

Preparation of Al-Ti-Sc master alloys and refining effects on the 6016 aluminum alloy

The 6016 aluminum alloy has good plasticity but low strength. In this work, Al-Ti-Sc master alloy was prepared by thermite reduction method in order to obtain an effective grain refiner with a simplified preparation process and a reduced cost. The refining effects of the ternary master alloy on the 6016 aluminum alloy were checked to improve the strength and plasticity simultaneously. The chemical reactions during the preparation process of the Al-Ti-Sc master alloy was studied by thermodynamic software of HSC 6.0. The content of Sc and Ti in the master alloy reaches 2.48 wt% and 1.4 wt%, respectively, on proper experimental conditions, and the main phases of the master alloys are α-Al and Al3(Sc,Ti) phase. In the refined alloys, the average grain size can reach 27 μm, and the ultimate tensile strength and the elongation after fracture reaches 280 MPa and 35% in cast state, respectively. Compared to the pristine 6016 aluminium alloy, the significantly enhanced strength and good plasticity of the refined alloys contribute to the combined effects of grain refinement and precipitated phase strengthening. For the fracture of low doped alloys, originates from cleavage fracture mechanisms, and for the ones with high dosages, ductile fracture becomes dominant.

Synthesis of Smart Packaging from Cellulose Acetate with The Addition of AgNO3 as An Antibacterial Substance

Synthesis of smart packaging from cellulose acetate with the addition of AgNO3 as an antibacterial substance has been investigated. The purpose of this study is to fabricate smart packaging from cellulose acetate with the addition of AgNO3 as an antibacterial substance. The method used was solution casting. In addition, this study was also characterizing the smart packaging, they included tensile strength and elongation percent test, antibacterial test, morphology analysis using SEM, and biodegradability test. The plastics obtained were clearly yellow, not easily damaged, a little thick, and the smooth surface and slightly bubbly. The largest tensile strength of plastic was 0.0661 MPa, it found in sample No. 2, while the smallest tensile strength was 0.027 MPa, it found in sample No. 1. The greatest elongation value at break was 5% found in sample No. 4, while the smallest elongation value at break was 3.5% in sample No. 3. The result of antibacterial test reported that the freshest mangoes were shown by samples No. 1 and No. 2; while the fast-rotting mangoes were shown in the sample No. 3 and No. 4. The results of the SEM test showed the presence of nano-sized particles that spreaded in the plastic body. The greatest degradability degree were sample No. 4 about 0.0009 g/day with the percentage of mass loss about 17.38%. Futhermore, cellulose acetate can be used as a basic material for making plastics. The addition of AgNO3 in plastic synthesis can help to delay the process of fruit spoilage caused by bacteria.

Seismic response and failure mechanism of ordinary concrete and UHTCC short columns reinforced with negative Poisson's ratio steel bars

The replacement of ordinary steel bars by negative Poisson's ratio (NPR) steel bars to improve the seismic performance of short columns is investigated in this study. NPR steel bars is a new type of reinforcement with negative Poisson's ratio effect and high strength and ductility. In this paper, six short column members were designed. Among them, P-RC1 and P-UHTCC1 short columns were used as controls, and the remaining four specimens were reinforced by NPR steel bars. The failure mode, cracking pattern, hysteresis characteristics, plastic deformation capacity, shear strength, stiffness degradation and energy dissipation capacity of the specimens were investigated through lateral cyclic loading tests. The experimental results showed that the shear capacity of short concrete columns reinforced with NPR steel bars increased by 20.91%−22.64% and the cumulative energy dissipation capacity increased by 45.7%−63.3%. The short UHTCC columns reinforced with NPR steel bars showed an increase in shear capacity of 23.08%−35.48% and an increase in cumulative energy consumption capacity of 17.3%−28.5%. And the RC columns shear strength prediction model based on GB50010–2010 specification is relatively reasonable to be used for the evaluation of shear strength of short columns reinforced with NPR steel bars.

Comparison of tearing test methods for elastomers on trouser test pieces and determination of tear strength of plastics using a tearing element

The process of tearing on trouser test pieces was studied on four types of materials according to GOST 262-93 for elastomers and according to POLYPLASTIC Group standard STO 73011750-009-2012 [3] for testing thermoplastic materials. It has been shown that when tested according to the POLYPLASTIC Group standard on materials of polyethylene group (using a tearing element), it is possible to realize an area of continuous tearing. Data on tear resistance values were obtained on four materials: plasticized PVC, polyethylene of blow molding grades, PU and silicone.