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1.
Polymers (Basel) ; 16(15)2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39125192

RESUMEN

In this paper, a new method involving a wear-resistant and reusable template is proposed for the preparation of high-mechanical-strength superhydrophobic polymer film based on wire electrical discharge machining (WEDM). A solid-liquid-contact-angle simulation model was established to obtain surface-texture types and sizes that may achieve superhydrophobicity. The experimental results from template preparation show that there is good agreement between the simulation and experimental results for the contact angle. The maximum contact angle on the template can reach 155.3° given the appropriate triangular surface texture and WEDM rough machining. Besides, the prepared superhydrophobic template exhibits good wear resistance and reusability. PDMS superhydrophobic polymer films were prepared by the template method, and their properties were tested. The experimental results from the preparation of superhydrophobic polymer films show that the maximum contact angle of the polymer films can be up to 154.8° and that these films have good self-cleaning and anti-icing properties, wear resistance, bending resistance, and ductility.

2.
Polymers (Basel) ; 16(15)2024 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-39125247

RESUMEN

Distinguished from traditional vulcanized rubber, which is not reusable, thermoplastic elastomer (TPV) is a material that possesses both the excellent resilience of traditional vulcanized rubber and the recyclability of thermoplastic, and TPVs have been widely studied in both academia and industry because of their outstanding green properties. In this study, new thermoplastic elastomers based on solution polymerized styrene butadiene rubber (SSBR) and thermoplastic elastomers (SEPSs/SEBSs) were prepared by the first dynamic vulcanization process. The high slip resistance and abrasion resistance of SSBR are utilized to improve the poor slip resistance of SEPSs/SEBSs, which provides a direction for the recycling of shoe sole materials. In this paper, the effects of different ratios of the rubber/plastic phase (R/P) on the mechanical properties, rheological properties, micro-morphology, wear resistance, and anti-slip properties of SSBR/TPE TPVs are investigated. The results show that the SSBR/TPE TPVs have good mechanical properties. The tensile strength, tear strength, hardness, and resilience of the TPVs decrease slightly with an increasing R/P ratio. Still, TPVs have a tensile strength of 18.1 MPa when the ratio of R/P is 40/100, and this reaches the performance of the vulcanized rubber sole materials commonly used in the market. In addition, combined with microscopic morphology analysis (SEM), it was found that, with the increase in the R/P ratio, the size of the rubber particles gradually increased, forming a stronger crosslinking network, but the rheological properties of TPVs gradually decreased; crosslinking network enhancement led to the increase in the size of the rubber particles, and the increase in the size of rubber particles made the material in the abrasion of rubber particles fall easily, thus increasing its abrasion volume. Through dynamic mechanical analysis and anti-slip tests, when the R/P ratio was 40/100, the tan δ of TPVs at 0 °C was 0.35, which represents an ordinary vulcanized rubber sole material in the market. The viscoelasticity of TPVs increased with the increase in the R/P ratio, which improved the anti-slip performance of TPVs. SSBR/TPE TPVs are expected to be used in footwear and automotive fields due to their excellent abrasion resistance and anti-slip performance.

3.
Nanomaterials (Basel) ; 14(14)2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-39057848

RESUMEN

To improve the wear resistance of the materials used for blades in engineering machinery, this study focused on the microstructural characteristics, mechanical properties, and wear behavior of HB500 grade wear-resistant steel developed using an optimized heat treatment system. To improve the temperature uniformity of the heat treatment furnace, the method of cyclic heating was used to heat the components. Carefully designing the quenching equipment, such as using a cross-shaped press, was employed to enhance the quenching effect and reduce the deformation of the steel plates. The crystal orientation analysis revealed a uniform and fine-grained microstructure, primarily characterized by plate-type tempered martensite, which indicated a good hardenability. The microstructure observations showed that the width of martensite is approximately 200 nm, with a significant presence of dislocations and carbides. Tensile tests and multi-temperature gradient impact tests indicated superior mechanical properties compared to similar grade wear-resistant steels, including a Rockwell hardness of 53, tensile strength of 1610 MPa, yield strength of 1404 MPa, and total elongation around 12.7%. The results of friction and wear experiments indicate that the wear rate decreases as the load increases from 100 N to 300 N, demonstrating an excellent wear resistance under a large load. Observations of the worn surfaces indicated that the wear mainly involved adhesive wear, fatigue wear, and oxidative wear. The properties' improvements were attributed to microstructure refinement and precipitation strengthening. This study indicates that designing a heat treatment system to control temperature uniformity and stability is feasible.

4.
ACS Appl Mater Interfaces ; 16(27): 35805-35814, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38916412

RESUMEN

Icing and fogging on optical material surfaces bring various problems in daily life. Recently, some photothermal coatings have been reported to prevent the condensation or freeze of water droplets by increasing the surface temperature. However, it is a great challenge to apply them in practical conditions due to their opaqueness and poor mechanical wear-resistant property. In this work, we constructed a robust transparent photothermal omniphobic coating with a simple dip-coating technique. In the coating system, photothermal polypyrrole nanoparticles are introduced into inorganic silica networks, and then polydimethylsiloxane (PDMS) brushes were grafted on the inorganic silica layer to endow the surface with omniphobicity and stain resistance. The transparency and photothermal capacity of the coating can be regulated by the deposition times of the coating. In addition, the coating has an excellent anti/deicing property and reduces ice adhesion obviously due to the existence of "liquid-like" PDMS brushes. More importantly, the coating presents outstanding mechanical wear-resistant and self-lubricating properties that can endure several thousand friction cycles without performance loss. The mechanically robust photothermal omniphobic coating gives a feasible approach to anti-icing and antifogging of transparent substrates under sunlight irradiation.

5.
Polymers (Basel) ; 16(9)2024 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-38732696

RESUMEN

The light weight and excellent mechanical properties of rubber foam means that it is widely applied in the aerospace, automobile, and military industries. However, its poor wear resistance contributes directly to a short service life and a waste of resources. Therefore, the design and development of high-wear-resistance rubber foam are of great importance. In this work, some nanoclay/rubber composite foams were prepared by blending NR/EPDM with different kinds of nanoclays containing layered double hydroxide (LDH), montmorillonite (MMT), and attapulgite (ATP) to indicate the effects of the kinds of nanoclays on the wear resistance and mechanical properties of nanoclay/rubber composite foams. The kinds of nanoclay/rubber composite foams were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The results showed that nanoclay has heterogeneous nucleation in composite foamed materials. The wear resistance of the composite foam materials with added nanoclay was significantly improved, and the MMT of the lamellar structure (increased by 43.35%) and LDH (increased by 38.57%) were significantly higher than the ATP of the rod-like structure (increased by 13.04%). The improvement in the wear resistance of the matrix was even higher. Compared with other foams, the wear resistance of the OMMT-NR/EPDM foam (increased by 58.89%) with a lamellar structure had the best wear resistance. Due to the increase in the lamellar spacing of the modified OMMT, the exfoliation of worn rubber molecular chains has little effect on the adjacent molecular chains, which prevents the occurrence of crimp wear and further improves the wear resistance of composite foaming materials. Therefore, this work lays the foundation for the manufacturing of rubber foams for wear-resistant applications.

6.
Materials (Basel) ; 17(10)2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38793474

RESUMEN

Low-alloy wear-resistant steel often requires the addition of trace alloy elements to enhance its performance while also considering the cost-effectiveness of production. In order to comparatively analyze the strengthening mechanisms of Mo and Cr elements and further explore economically feasible production processes, we designed two types of low-alloy wear-resistant steels, based on C-Mn series wear-resistant steels, with individually added Mo and Cr elements, comparing and investigating the roles of the alloying elements Mo and Cr in low-alloy wear-resistant steels. Utilizing JMatPro software to calculate Continuous Cooling Transformation (CCT) curves, conducting thermal simulation quenching experiments using a Gleeble-3800 thermal simulator, and employing equipment such as a metallographic microscope, transmission electron microscope, and tensile testing machine, this study comparatively investigated the influence of Mo and Cr on the microstructural transformation and mechanical properties of low-alloy wear-resistant steels under different cooling rates. The results indicate that the addition of the Mo element in low-alloy wear-resistant steel can effectively suppress the transformation of ferrite and pearlite, reduce the martensitic transformation temperature, and lower the critical cooling rate for complete martensitic transformation, thereby promoting martensitic transformation. Adding Cr elements can reduce the austenite transformation zone, decrease the rate of austenite formation, and promote the occurrence of low-temperature phase transformation. Additionally, Mo has a better effect on improving the toughness of low-temperature impact, and Cr has a more significant improvement in strength and hardness. The critical cooling rates of C-Mn-Mo steel and C-Mn-Cr steel for complete martensitic transition are 13 °C/s and 24 °C/s, respectively. With the increase in the cooling rate, the martensitic tissues of the two experimental steels gradually refined, and the characteristics of the slats gradually appeared. In comparison, the C-Mn-Mo steel displays a higher dislocation density, accompanied by dislocation entanglement phenomena, and contains a small amount of residual austenite, while granular ε-carbides are clearly precipitated in the C-Mn-Cr steel. The C-Mn-Mo steel achieves its best performance at a cooling rate of 25 °C/s, whereas the C-Mn-Cr steel only needs to increase the cooling rate to 35 °C/s to attain a similar comprehensive performance to the C-Mn-Mo steel.

7.
Materials (Basel) ; 16(19)2023 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-37834622

RESUMEN

Superhydrophobic coatings are limited by complex preparation processes and poor mechanical durability in practical applications. In this study, a mechanically robust superhydrophobic composite coating was applied to an aluminum surface that underwent processing with a nanosecond laser (referred to as a superhydrophobic aluminum surface). It exhibits a high water contact angle (WCA) of 158.81°, a low sliding angle (SA) of less than 5°, and excellent self-cleaning ability. The wear test shows its durability, and the corrosion test shows its excellent corrosion resistance. This study provides a framework for the preparation of robust superhydrophobic surfaces that may have potential applications in many fields.

8.
Materials (Basel) ; 16(17)2023 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-37687549

RESUMEN

The formation mechanism of the delayed crack after flame cutting and mechanical properties in thick NM550 wear-resistant steel are studied by optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and an electron backscattered diffractometer. The delayed crack is formed at the segregation zone (SZ) located in the center of the 65 mm thick steel plate. The strength of the non-segregation zone (NSZ) with a martensite microstructure is slightly higher than that of SZ with a mixture microstructure of martensite plus bainite, and the plasticity of NSZ is significantly better than that of SZ. There exists a more severe segregation in the SZ, and only a slight segregation in the NSZ. The average grain sizes of the segregation bands in the NSZ and SZ are 15.72 µm and 6.76 µm, respectively. The number density of TiN larger than 5 µm in the NSZ and SZ is 0.031 and 1.156 number/mm2, respectively. Therefore, a high hardness segregation band with fine grains and a high dislocation density, along with the large number of coarse TiN inclusions within it, results in delayed cracking. For TiN inclusions close to the crack, microvoids or microcracks around the TiN are formed, and the delayed crack will propagate along the edge of the TiN or through the TiN inclusions.

9.
Materials (Basel) ; 16(14)2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37512424

RESUMEN

Accumulated ice has brought much damage to engineering and people's lives. The accumulation of ice can affect the flight safety of aircraft and lead to the failure of cables and power generation blades; it can even cause damage to human life. Traditional anti-icing and de-icing strategies have many disadvantages such as high energy consumption, low efficiency, or pollution of the environment. Therefore, inspired by animal communities, researchers have developed new passive anti-icing materials such as superhydrophobic material. In this paper, the solid surface wetting phenomenon and superhydrophobic anti-icing and de-icing mechanism were introduced. The methods of fabrication of superhydrophobic surfaces were summarized. The research progress of wear-resistant superhydrophobic coatings, self-healing/self-repairing superhydrophobic coatings, photothermal superhydrophobic coatings, and electrothermal superhydrophobic coatings in the field of anti-icing and de-icing was reviewed. The current problems and challenges were analyzed, and the development trend of superhydrophobic materials was also prospected in the field of anti-icing and de-icing. The practicality of current superhydrophobic materials should continue to be explored in depth.

10.
Materials (Basel) ; 16(6)2023 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-36984016

RESUMEN

This paper discusses the impact of coal abrasive materials of varied petrographic composition and claystones containing admixtures of coal matter on the surface wear of wear-resistant martensitic steels. Wear tests were conducted at a test stand for three petrographic varieties of hard coal: vitrinite, clarinite, and durinite, and five samples of claystone. These tests revealed no significant effect of the type of coal abrasive used on the value of mass loss from the surface of the wear-resistant steel samples. The reason behind the foregoing is the observed tendency of coal abrasives, irrespective of their petrographic variety, to penetrate surface irregularities, especially those attributable to previous surface treatment of the samples and the impact of wear products. The dominant forms of surface damage were surface fatigue chipping and scratches caused by the particles which detached themselves from the surface of the steel samples, as observed for all the analysed coal variants. On the surfaces of the samples seasoned in the presence of claystones, highly varied forms of damage were observed: microcutting, scaly surface cracks, delamination, and deep cracks. In these cases, it was possible that the abrasive grains had been pressed into the steel surface irregularities, but no layered forms of the pressed-in abrasive material were observed to have developed. The paper also presents a model for the formation of coal films and discusses their possible effect on wear minimisation.

11.
Materials (Basel) ; 16(3)2023 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-36770154

RESUMEN

This study investigates the effect of deposition pressure on the microstructure and tribological properties of CrAgCeN coatings synthesized via unbalanced magnetron sputtering. The CrAgCeN coatings presented a face-centered cubic structure. As the deposition pressure increased, the surface grain topography of the CrAgCeN coatings transformed from a looser pyramidal structure to a denser structure, while their hardness H and elastic modulus E first increased and then decreased. The strengthening effect was mainly attributable to Ag and Ce elements. Conversely, the coefficient of friction (COF) and wear rates of the coatings reduced and then increased. Under 0.6-Pa deposition pressure, the COF and wear rate of the CrAgCeN coating were minimized (0.391 and 3.2 × 10-7 mm3/(N·m), respectively) while the H and E were maximized (14.2 and 206.2 GPa, respectively). The values of hardness, wear resistance, resistance of elastic strain to failure (H/E) and resistance to plastic deformation (H3/E2) were improved for the coatings by Ce. The wear mechanisms were adhesion and delamination. The wear mechanisms were adhesion and delamination. Selecting the appropriate deposition pressure can improve the tribological properties of the CrAgCeN coatings. The received results of research in this study allow us to establish a rational coating composition for deposition on tools providing an increase in machining efficiency of the materials used in engineering. CrAgCeN coating with excellent properties may be applied to steel substrate through the combined action of corrosion, high temperature and mechanics.

12.
Materials (Basel) ; 15(24)2022 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-36556834

RESUMEN

This paper focuses on the microstructure and tribological properties of novel hardfacing alloy based on Fe-C-Mn-B doped with Ni, Cr, and Si. The 4 mm-thick coating was deposited on the AISI 1045 carbon steel by the MIG-welding method using flux-cored wires in three passes. The transition zone thickness between the weld layers was ~80 µm, and the width of the substrate-coating interface was 5-10 µm. The following coating constituents were detected: coarser elongated M2B borides, finer particles of Cr7C3 carbides, and an Fe-based matrix consisting of ferrite and austenite. The nanohardness of the matrix was ~5-6 GPa, carbides ~16-19 GPa, and borides 22-23 GPa. A high cooling rate during coating fabrication leads to the formation of a fine mesh of M7C3 carbides; borides grow in the direction of heat removal, from the substrate to the friction surface, while in the transition zone, carbides become coarser. The dry sliding friction tests using a tribometer in PoD configuration were carried out at contact pressure 4, 7, 10, and 15 MPa against the AISI 1045 carbon steel (water-quenched and low-tempered, 50-52 HRC). The leading wear phenomenon at 4 and 7 MPa is fatigue, and at 10 and 15 MPa it is oxidation and delamination.

13.
Materials (Basel) ; 15(19)2022 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-36234349

RESUMEN

The research was conducted on a thick-walled welded joint between the HTK 900H wear-resistant steel plates and the A6 cast profile. The aim of the experiment was to produce a joint with the relevant performance requirements, i.e., a good abrasion resistance joint in the weld face area while ensuring its proper plasticity. The welded joint was made using the MAG PULSE and the high-performance MAG TANDEM methods under automated conditions using the linear welding energy ranging from 1.2 to 2.2 kJ/mm for the different joint regions. The scope of the research included both non-destructive and destructive testing. The non-destructive visual (VT), magnetic-particle (MT), and ultrasonic (UT) tests revealed a good quality of the welded joint with no significant welding imperfections. The microstructure of the welded joint in the weld zone was characterized by a dominant volume fraction of martensite/bainite. The measurement of hardness near the face of the weld confirmed obtaining similar values for this parameter. The HTK 900H steel was characterized by hardness at the level of 383 HV10, whereas the A6 cast-328 HV10, and the weld-276 HV10. At the same time, the analyzed joint showed high ductility in the range of 86 to 159 J. The tests carried out showed that the linear energy control allowed a welded joint with the required performance characteristics to be obtained.

14.
Front Chem ; 10: 952919, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36262341

RESUMEN

The facile and low-cost fabrication of fluorine-free superhydrophobic metal surfaces for anticorrosion remains a challenging issue. Here, we report a superhydrophobic coating based on polyacrylate/SiO2 nanoparticles/graphene oxide sheets through a simple yet environmentally friendly method. The as-prepared composite coating sprayed on metal surfaces exhibits excellent superhydrophobic and corrosion-resistant properties. Furthermore, the coating surface possesses good anti-wear performance and remains superhydrophobic after harsh abrasion tests. Prospectively, the developed non-fluorinated superhydrophobic coating opens up opportunities for the application in industrial anticorrosion field.

15.
Polymers (Basel) ; 14(19)2022 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-36236155

RESUMEN

Silica and carbon black are the most important reinforcing systems in rubber formula. In the process of continuous optimization of the formula, silica gradually replaces carbon black by its characteristics. In view of the wear problem of the components of the mixer chamber caused by the increase in the proportion of silica in the formula, this research applied carbon matrix composite (CMC) materials to wear-resistant plate materials, and compared them with common wear-resistant (CWR) plate materials to explore the impact of replacing CWR plate with CMC on improving wear resistance and mixing effect. The results showed that compared with the CWR plate, CMC wear-resistant plate showed characteristics of a high friction coefficient and low wear rate (reduced by about 23%) in the mixing process of silica compound. However, the friction behavior of carbon black compound and carbon matrix composite wear-resistant plate showed an opposite trend, where the friction coefficient and wear rate increased simultaneously, especially the wear rate that increased by about 35%. The main reasons for the experimental results were related to the characteristics, elemental composition and surface morphology of carbon matrix composite, silica and carbon black. The experimental results also indicated that the carbon matrix composite wear-resistant plate is more suitable for a silica mixing process, and the increasing friction coefficient with decreasing wear rate of wear-resistant plate can further improve the importance of effective friction in mixing and prolonging the service life of wear-resistant plate.

16.
Materials (Basel) ; 15(18)2022 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-36143774

RESUMEN

There is a serious wear problem in the middle plate of scraper conveyors, which causes the problems of high transportation cost, low efficiency, and a lot of material waste. Therefore, it is necessary to study the wear performance of middle plate materials. A new high-titanium low alloy wear-resistant steel (ZM4-13) and a typical material (NM400) for middle plates are studied in this paper. The findings show that the mass loss of ZM4-13 and NM400 rises with the increase of coal gangue percentage. They do not increase monotonically with the change of pH value, and there is a critical value: the critical value of NM400 is between 6-8, and the critical value of ZM4-13 is between 7-9. When the pH value is less than the critical value, the mass loss decreases with the increase of pH value; when the pH value is greater than the critical value, the mass loss increases with the increase of pH value. Under the condition of high gangue and neutral solutions, ZM4-13 has better wear resistance. Its wear resistance can reach up to 1.09-2.10 times compared with NM400. The in-situ precipitated TiC particles are dispersed in ZM4-13. The high hardness of the TiC precipitation area in ZM4-13 hinders the plowing of hard particles and the plastic deformation of surface materials, so ZM4-13 is more wear-resistant than NM400, especially suitable for the harsh working conditions of coal mine production.

17.
Materials (Basel) ; 15(13)2022 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-35806519

RESUMEN

In this study, we analyzed the quaternary Fe-C-Mn-B system to create new eutectic cast alloys for coating deposition and additive manufacturing. Experimental samples were fabricated via the wire arc manufacturing method with argon shielding using Kemppi Pro 5200 Evolution equipment. Annealing was performed in a vacuum electric furnace at 1273 K for 350 h. For phase analyses, Jeol Superprobe 733 equipment was used. Metallographic and differential thermal analyses were used to reveal the eutectic structure of the samples. Examinations of the quaternary Fe-C-Mn-B system demonstrated that several eutectic alloys existed in the system. Four isothermal pseudo-ternary sections of the Fe-C-Mn-B system were studied: "Fe3B"-Fe3C-"Fe3Mn"; Fe2B-"Fe2C"-"Fe2Mn"; "Fe3B"-Fe3C-"Fe1.2Mn"; "Fe23B6"-"Fe23C6"-"Fe23Mn". Broad eutectic concentrations enabled us to overcome parameter fluctuations during additive manufacturing. In each isothermal section, two dissimilar phase regions were determined: one with a ternary Fe-C-B composition and the other with a ternary Fe-C-Mn composition. Depending on the manganese content, two types of solid solutions could be formed: (Fe, Mn)α or (Fe, Mn)γ.

18.
Angew Chem Int Ed Engl ; 61(26): e202204410, 2022 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-35412006

RESUMEN

In this study, a novel surface initiated polymerization (SIP) method was developed from organic-inorganic hybrid persistent initiator coating (PIC) that embeds initiator molecules into inorganic silica sol-gel layer. Comparing with traditional silane initiator surface that prepared by chemical vapor deposition (CVD) method, the PIC can effectively improve the mechanical stability of initiator that was able to endure ten-thousand times of friction cycles. Besides, it allows polymer grafting from sub-surface and so the grafted brushes, poly 3-sulfopropyl methacrylate potassium salt (pSPMA) on the PIC were also much more wear-resisting than those prepared by the traditional ways. More importantly, the PIC could still trigger new polymerization reaction when the grafted brushes were worn off. In addition, the PIC is universal and can be covered on different substrates including glass, metals and plastics, etc. to realize functionalization of these materials. The approach may pave technological way for the application of surface grafted polymer brushes.

19.
Materials (Basel) ; 15(3)2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-35160676

RESUMEN

As a commonly reinforcing phase in wear-resistant materials, TiC is often added into wear-resistant materials to improve the wear resistance. The independently developed stepped molds with variable thicknesses were used to prepare the TiC-reinforced steels with the same composition though melt solidification processing to study the effect of the solidification rate on the particle size and wear performance. The effect of the hot rolling compression ratio on the particle size and wear performance was also studied. The length and aspect ratios of the particles in heat-treated TiC-reinforced steels with different billet thicknesses and rolling compression ratios were measured. With the increasing in the billet thickness and the decreasing in the rolling compression ratio, the length and aspect ratio of the particles increased in heat-treated TiC-reinforced steels, and the hardness decreased slightly. The three-body abrasive wear behavior of the TiC-reinforced steels was conducted using a standard dry sand rubber wheel wear testing procedure, and the modeling of the wear mechanism was established. The particle size is the main factor affecting wear resistance when the hardness of TiC-reinforced steels is similar. When the particles size is moderate, about 2-6 µm, the particle can break the sand tip and hinder the sand tip from sliding on the surface. In this manner, the mass loss decreased and the wear resistance improved. The large particles will be broken easily by the abrasive, and the small particles are removed easily by the abrasive in the wear process. So, the large and small particles cannot effectively prevent the damage of the abrasive to the matrix, and they have less of an effect on improving wear resistance.

20.
Micromachines (Basel) ; 12(11)2021 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-34832738

RESUMEN

This paper presents a simple and reliable routine for batch fabrication of wear-resistant and conductive probe with a PtSi tip. The fabrication process is based on inductively coupled plasma (ICP) etching, metal evaporation, and annealing. Si tips with curvature radii less than 10 nm were produced with good wafer-level uniformity using isotropic etching and thermal oxygen sharpening. The surface roughness of the etched tip post was reduced by optimized isotropic etching. The dependence of the platinum silicide morphology on annealing conditions were also systematically investigated, and conductive and wear-resistant probes with PtSi tips of curvature radii less than 30 nm were batch fabricated and applied for scanning piezoelectric samples.

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