MATERIALS SCIENCE FORUM
·
2016
·
IF 0
Yu Mei Zhou,Feng Lin Zhang,Peng Cheng Li,Kun Bai,Shang Hua Wu
AlMgB14 is a very hard and brittle material which need be modified for utilizing as cutting tool materials. In present study, TiB2 and Ni3Al were used to strengthen and toughen AlMgB14 material. The microstructure of the AlMgB14-TiB2-Ni3Al composites was analysized by scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX) and an X-ray diffractometer (XRD). The hardness and fracture toughness of the AlMgB14-TiB2Ni3Al composites were also examined. The results showed that the major phases in AlMgB14-Ni3Al composites were TiB2, AlMgB14, MgAl2O4 , Ni3Al and NiAl. With the increasing of the amount of Ni3Al, more intergranular fractured features can be found in the fractured surface of the composites, the hardness and fracture toughness of the composites were both decreased comparing to the synthesised AlMgB14. The AlMgB14-TiB2-4wt.% Ni3Al composite has a hardness of 28.1 Gpa and a fracture toughness of 3.14 MPa·m1/2.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
Nanomaterials
·
2021
·Vol. 11
·期 7
·1854
·
IF 5.076
Xiuru Xu,Chubin He,Feng Luo,Hao Wang,Zhengchun Peng
Robust conductive hydrogels are in great demand for the practical applications of smart soft robots, epidermal electronics, and human–machine interactions. We successfully prepared nanoparticles enhanced polyacrylamide/hydroxypropyl guar gum/acryloyl-grafted chitosan quaternary ammonium salt/calcium ions/SiO2nanoparticles (PHC/Ca2+/SiO2NPs) conductive hydrogels. Owing to the stable chemical and physical hybrid crosslinking networks and reversible non-covalent interactions, the PHC/Ca2+/SiO2NPs conductive hydrogel showed good conductivity (~3.39 S/m), excellent toughness (6.71 MJ/m3), high stretchability (2256%), fast self-recovery (80% within 10 s, and 100% within 30 s), and good fatigue resistance. The maximum gauge factor as high as 66.99 was obtained, with a wide detectable strain range (from 0.25% to 500% strain), the fast response (25.00 ms) and recovery time (86.12 ms), excellent negligible response hysteresis, and good response stability. The applications of monitoring the human’s body movements were demonstrated, such as wrist bending and pulse tracking.Keywords:hydrogels;toughness;wearable sensors
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2022
·Vol. 32
·期 39
·2204823
·
IF 19.924
Wei Cui,Yong Zheng,Ruijie Zhu,Qifeng Mu,Xiaoyu Wang,Zhisen Wang,Shengqu Liu,Min Li,Rong Ran
Ion is one of the most common additives that can impart electrical conductivity to insulating hydrogels. The concurrent toughening effect of ions, however, is often neglected. This work reports the extreme toughening of hydrogels via the synergistic effect of cations and anions, without the need for specific structure design or adding other reinforcements. The strategy is to equilibrate a physical double network hydrogel consisting of both multivalent cation- and kosmotropic anion-sensitive polymers in specific salt solutions that can induce cross-linking and salting-out simultaneously. Both effects are proven positive to boost the mechanical performance and electrical conductivity of the original weak gel, and result in a tough conductive gel with exceptional physical properties, achieving significant enhancements in fracture stress, fracture energy, and ionic conductivity by up to 530-, 1100-, and 4.9-folds, respectively. The optimal fracture stress and toughness reach approximately 15 MPa and 39 kJ m –2 , exceeding most state-of-the-art tough conductive hydrogels. Meanwhile, a satisfactory ionic conductivity of 1.5 S m –1 is attained. The presented simple strategy is also found generalizable to other salt ions and polymers, which is expected to expand the applicability of hydrogels to conditions involving demanding mechanical durability.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
MACROMOLECULES
·
2025
·
IF 5.2
Meijia Gong,Luping Wang,Kaiyang Hou,Kaiqiang Zhang,Xu Wang
Optimizing supramolecular interactions is crucial for enhancing the damage resistance of elastomers under extreme mechanical stresses. However, the underlying mechanisms remain not fully understood, making targeted design challenging. This study thoroughly investigates a series of polyurethane elastomers and presents a strategy to enhance elastomer damage resistance by tuning the number and strength of hydrogen bonds at the hard–soft interface. Within these elastomers, we find that the hardness is positively correlated with the number and strength of hydrogen bonds, while toughness increases with the number of hydrogen bonds, reaching a maximum at moderate bond strength. Elastomers with both high hardness and toughness demonstrate superior impact resistance, while the best tear resistance is achieved with moderate hardness and high toughness. By balancing hydrogen bond acceptors in the soft segment with donors in the hard segment, an elastomer with an exceptional impact strength of 9.2 MJ m–2 is obtained, and tear resistance of 275.0 kJ m–2 is achieved by modulating the interaction strength. This research clarifies structural factors influencing damage resistance, including the number and strength of hydrogen bonds at the hard–soft interface, offering valuable insights for the design of highly impact- and tear-resistant elastomers.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2017
·Vol. 57
·期 12
·1277-1284
·
IF 1.449
Jia Qiu,Fei Liu,Junwu Zhang,Jing Chen,Haining Na,Jin Zhu
The controllable polyesters with high overall performance are obtained by tuning the stereostructure of 1,4-cyclohexylene ring moieties (CHRMs) in poly(butylene adipate- co −1,4-cyclohexanedicarboxylate) (PBAC). After increasing the number of irregular cis -CHRMs in the polyester, PBAC can transform from semicrystalline polymer to amorphous one. PBAC with 58% cis -CHRMs starts to exhibit good elasticity with shape recovery of 60% at 250% deformation, indicating the transition from plastic to thermoplastic elastomer. Through blending with polylactic acid (PLA), the elastic PBAC greatly enhances the impact strength of PLA to 7.5 kJ/m 2 . While the tensile elongation at break is dramatically improved to 161% with the addition of plastic PBAC. The mechanism related to the stereostructure of non-planar ring of PBAC on the properties of PLA is also analyzed. Therefore, this research suggests a particular way to build non-planar ring contained polyesters to modify PLA with high toughness. POLYM. ENG. SCI., 57:1277–1284, 2017. © 2017 Society of Plastics Engineers
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2022
·Vol. 19
·期 4
·1916-1928
·
IF 2.328
Xiao-Chun Deng,Kai-Fei Wang,Guo-Hua Zhang
Combining spray drying and in situ synthesized technology, WC–10Co cemented carbide with uniform composition was prepared by vacuum sintering. The effects of Al 2 O 3 and additions of different rare-earth oxides (La 2 O 3 , Y 2 O 3 and CeO 2 ) on the microstructure and mechanical properties of WC–10Co were investigated. As the Al 2 O 3 content increased from .5 to 2 wt%, the hardness of the sintered sample increased, whereas the relative density and fracture toughness decreased. Compared with the addition of .5 wt% Al 2 O 3 , the WC–10Co alloy with .5 wt% rare-earth oxides had higher hardness. In addition, compared with the alloy without an inhibitor (.80 μm), after adding .5 wt% Al 2 O 3 , La 2 O 3 , Y 2 O 3 and CeO 2 , the WC grain sizes were reduced to .73, .65, .71 and .62 μm, respectively, which indicated that the addition of Al 2 O 3 and rare-earth oxides could refine WC grain during sintering. Among these additives, CeO 2 had the best effect. With the addition of .5 wt% CeO 2 , the hardness and the fracture toughness increased from 1299 to 1710 HV 30 and from 16.18 to 18.90 MPa m 1/2 , respectively.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2023
·
IF 6
Hongxu Meng,Zhisong Li,Linbo Wu
Poly(ethylene 2,5-furandicarboxylate) (PEF) is an important biobased polyester with not only high glass transition temperature ( T g ), excellent strength and rigidity but also superior gas barrier properties. However, its poor ductility could limit its applications. In this study, 2,5-thiophenedicarboylic acid (TDCA) was used to modify PEF by copolycondensation. By introducing 10–40 mol% TDCA, poly(ethylene 2,5-thiophenedicarboxylate-co-2,5-furandicarboxylate) (PEThF) copolyesters with intrinsic viscosity of 0.63–0.77 dL/g were synthesized and characterized with 1 H NMR, DSC, TGA, etc . The copolyesters are all amorphous polymers. Brittle-ductile transition was observed during tensile testing of PETh 10 F (PEThF containing 10 mol% 2,5-thiophenedicarboxylate unit). PEThFs containing 20–30% 2,5-thiophenedicarboxylate unit showed not only clearly improved ductility but also well-maintained performance advantages of PEF including high T g (84–81 °C), modulus (∼3.2 GPa), strength (yielding 95 MPa, breaking 60 MPa) and oxygen barrier (5.4–5.0 times PET).
研究领域:
材料科学
·
聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Binjie Zhang,Xianchang Peng,Zhengzhi Mu,Shichao Niu,Zhiwu Han,Luquan Ren
Mantis shrimps deliver one of the fastest strikes with their powerful dactyl clubs. The kinematic energy derived by a saddle storing and releasing mechanical energy with large deformation. As an exoskeleton, the toughness of saddles can achieve a remarkable value ≈15.28 ± 2.32 MJ m −3 , which exceeds most bulk natural materials. The excellent toughness of saddles is mainly attributed to the synergy of the helical mineralized fiber architectures and interlaminar fibrils. The interlaminar fibrils connect adjacent mineralized fiber layers closely, enhancing the toughness through viscoelastic deformation during sliding and separating of adjacent layers. They further cooperate with rigid interlacing fiber structure induced by helical structure to transform little normal strain to large shear strain utilizing incompressibility of soft fibrils further to enhance strain energy for toughening. Inspired by unique laminated saddles, the laminate composites are designed with basalt fabrics achieving remarkable fracture toughness to solve the problem of delamination in traditional laminate composites with poor interlaminar toughness. The Mode I and Mode II interlaminar fracture toughness of bio-inspired laminate composites respectively increase by 44% and 118% reaching 906.8 and 1394.6 J m −2 , which provides an innovative bionic strategy for designing new generation structural engineering materials with excellent mechanical properties.
研究领域:
仿生学
·
材料科学
·
生物力学
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL SPRAY TECHNOLOGY
·
2025
·
IF 3.3
Zhang Jian,Chen Hongxuan,Pang Xiaotong,Liu Shilong,Misra R. D. K.,Sun Junhao
Currently, surface coatings on agricultural machinery are crucial for extending service life. However, achieving coating strength and toughness remains a challenge. In this paper, two types of high-hardness iron-based coatings, referred as S1 and S2, were prepared by modulating the Mo/V ratio in the Fe-C-V-Mo-B system, and their microstructural evolution and property changes were investigated. The results show that the S1 coating primarily consist of martensitic matrix, spherical VC, blocky Mo 2 B, and a small amount of skeleton-like Mo 2 B. In contrast, the S2 coating consist of martensitic matrix, petal-like VC, and skeleton-like Mo 2 B. Compared with S1, the VC volume fraction in S2 increases by 6.5%, and the Mo 2 B volume fraction increases by 16.3%. The average microhardness of S1 and S2 coatings are 737 HV 0.5 and 954 HV 0.5 , respectively, indicating that the S2 coating exhibits a 22.7% higher microhardness compared with S1. The average friction coefficients of S1 and S2 coatings are 0.434 and 0.398, respectively. Furthermore, the wear loss of S2 coating is approximately half that of S1. The fracture toughness of S1 and S2 coatings are 51.9 MPa·m 1/2 and 51.7MPa·m 1/2 , respectively. Fracture analysis reveals that the skeleton-like eutectic structure in S2 can deflect cracks generated by impact, increase the length of propagation path, and improve the toughness of coating. It allows S2 coating to achieve high hardness and wear resistance, while maintaining toughness comparable to S1 coating. This study provides a theoretical basis for the design and development of iron-based coatings with high hardness, high abrasion resistance, and impact resistance for agricultural machinery.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2025
·
IF 9.2
En-Jiang Liu,Ding-ding Lü,Bai-Chuan Lu,Run-Ze Hu,Shi-Wen Guo,Chen-Man Zong,Xiao-Hui Yao,Xue-Yang Wang,Tao Chen,Ai-jun Wan,Dong-Yang Zhang
In recent years, many strategies have been developed to enhance the mechanical properties of hydrogels. However, due to the complex process, the addition of non-green crosslinking agents and the use of high concentration salt solutions will lead to increased costs, resource waste and environmental pollution. In addition, the synergistic improvement of strength and toughness of hydrogels is still challenging. Herein, a general green strategy of solid salting-out to improve the strength and toughness of hydrogels is reported. This strategy can induce the directional phase separation of water molecules in the hydrogel, promoting the close layer-by-layer self-assembly of the PVA molecular chain. Compared with liquid salting-out, solid salting-out has a more significant improvement in the strength of hydrogels, and solid salt blocks can be recycled and reused. A PVA hydrogel prepared by the solid salting-out method showed both high strength and toughness that were 1962- and 1900-fold of those before solid salting-out, respectively. The strength and toughness of the hydrogel can be further improved to 109.06 MPa and 125.73 MJ m−3 by inducing the collaborative self-assembly of cellulose nanofibers and PVA molecular chains. As a general strategy, solid salting-out could enhance various hydrogels composed of materials such as silk, gelatin, and cotton staple cellulose. Thus, this study not only provides a simple method for the strengthening and toughening of hydrogels but also has potential applications in the fields of biological implants because of the favorable biocompatibility of the prepared hydrogels.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2023
·
IF 8.7
Lei Liang,Xianxian Sun,Yuanhao Ning,Shasha Wang,Weilong Yin,Yibin Li
The process of toughening brittle ceramics is challenging but important for broadening their range of applications. Extensive studies on toughening brittle alumina (Al 2 O 3 ) ceramics at room temperature have been conducted; however, significantly increasing their toughness at high temperatures remains a challenge. Here, we propose the use of two-dimensional Ti 3 C 2 T x MXene ceramics with high thermal stability to effectively toughen Al 2 O 3 ceramics at high temperatures via a nacre-like structure strategy. The fracture toughness (K Jc ) of the as-prepared MXene/Al 2 O 3 nanocomposite at 1000 °C is 6.02 MPa m 1/2 , 2.4 times that of pure Al 2 O 3 (2.51 MPa m 1/2 ). Moreover, it maintains relatively high strength at 1000 °C (∼193 MPa). The toughening mechanisms - crack deflection, bifurcation and bridging effects - are obtained via in situ observation of crack propagation and finite element simulation. Our novel strategy provides a universal solution to improve the toughness of brittle ceramics at high temperatures and in some special environments.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
DOI
高影响因子
Materials
·
2019
·Vol. 12
·期 10
·1663
·
IF 2.972
Yuanping Jiang,Cong Yan,Kai Wang,Dawei Shi,Zhengying Liu,Mingbo Yang
Polylactic acid (PLA) holds enormous potential as an alternative to the ubiquitous petroleum-based plastics to be used in packaging film and agricultural film. However, the poor viscoelastic behavior and its extremely low melt strength means it fails to meet the requirements in film blowing processing, which is the most efficient film processing method with the lowest costs. Also, the PLA’s brittleness and insufficient gas barrier properties also seriously limit PLA’s potential application as a common film material. Herein, special stereocomplex (SC) networks were introduced to improve the melt strength and film blowing stability of PLA; polyethylene glycol (PEG) was introduced to improve PLA’s toughness and gas barrier properties. Compared with neat poly(l-lactide) acid (PLLA), modified PLA is stable in the film blowing process and its film elongation at break increases more than 18 times and reaches over 250%, and its O2permeability coefficient decreased by 61%. The resulting film material also has good light transmittance, which has great potential for green packaging applications, such as disposable packaging and agricultural films.Keywords:PLA;biodegradable films;toughness;film blowing
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）