Comprehensive Mechanical Properties Research Articles

A novel cast Co68Al18.2Fe6.5V4.75Cr2.55 dual-phase medium entropy alloy with superior high-temperature performance

A newly-designed Co68Al18.2Fe6.5V4.75Cr2.55 medium entropy alloy (MEA) with FCC + B2 structure exhibits not only an excellent strength-ductility combination at room temperature, but also an outstanding high-temperature mechanical properties in particular. The phase formation, microstructure and deformation mechanism of this designed dual-phase MEA at room and high temperatures were investigated and discussed in detail. Based on experimental results (XRD, SEM and TEM) and theoretical analysis (calculated diagram and empirical thermodynamic parameters), it is demonstrated that this newly-designed MEA consists of a dual-phase structure of a face-centered-cubic (FCC) phase (70.3 vol %) plus chemically ordered body-centered cubic phase (B2) (29.7 vol %). Meanwhile, the FCC phase is enriched with Co, Fe and Cr elements, while the B2 phase is enriched with Al and Co elements. Furthermore, compared with some HEAs/MEAs and commercial alloys, this newly-designed dual-phase MEA exhibits excellent strength-ductility combination with a high compressive yield strength of ∼1254 MPa, a fracture strength of ∼2657 MPa and a large compressive plasticity of ∼34.6 % at room temperature. In particular, the studied MEA also shows an outstanding high-temperature performance with an ultrahigh yield strength of ∼1213 MPa at 600 °C and ∼626 MPa at 800 °C, respectively. The excellent comprehensive mechanical properties of this designed dual-phase MEA at both room and temperatures mainly originate from synergy effect of alternate FCC + B2 structure and strengthening contributions of B2 phase. These important findings not only reveal the deformation and strengthening mechanisms of the newly-designed dual-phase MEA, but also provides an effective alloy design strategy for developing advanced structural materials serving as a wide range of temperature.

Enhancement effects of FeCoNiCrMn high-entropy alloy doping on the Ti(C, N)-based cermets: Microstructure and mechanical properties

The enhancement effects of doping Ti(C, N)-based cermets with different contents of FeCoNiCrMn (HEA, high entropy alloy) on the mechanical properties, microstructure, cutting performance and high temperature bending strength of the Ti(C, N)-based cermets were investigated. Ti(C, N) particles had good wettability to the metal liquid phase of HEA, and with the increase of HEA content, the strength of the binder gradually improved. When the content of HEA was 12%, the cermets had the best comprehensive mechanical properties, with a relative density of 99.8%, Vickers hardness of 19.5 ± 0.2 GPa, fracture toughness of 8.2 ± 0.1 MPa·m1/2, and bending strength of 1229 ± 82 MPa. Compared with Co binders, HEA binders had better softening resistance at high temperatures. When the content of HEA exceeded 6%, the bending strength at 700 °C of the Ti(C, N)-based cermet tools were enhanced by 78%–96%, and the cutting life was increased by 35%–65%.

Effect of Sc on the recrystallization behavior and mechanical properties of Al-Zn-Mg-Cu-Zr alloys under isothermal multidirectional compression

To better achieve grain refinement and further optimize the comprehensive mechanical properties of Al-Zn-Mg-Cu-Zr alloys, this paper investigates the effect of trace Sc on the recrystallization behavior of Al-Zn-Mg-Cu-Zr alloys under isothermal multidirectional compression (IMC) and the mechanical properties in two-stage aging state. It was discovered that the addition of Sc enhanced the tensile and yield strengths of the alloys by 3.8% and 4.3%, respectively, and simultaneously increased the elongation from 13.4% to 15.4%. The OM, EBSD and TEM techniques were used to characterize the microstructure of the alloy. The results showed that the Al3(Sc,Zr) phase produced by the addition of 0.25% Sc not only refines the grains, but also changes the recrystallization behavior of the alloy by pinning the dislocations and (sub) grain boundaries in the combination of IMC deformation. It inhibits the generation of geometric dynamic recrystallization (GDRX) grains and the nucleation of discontinuous dynamic recrystallization (DDRX) grains but promotes the formation of continuous dynamic recrystallization (CDRX) as the predominant mode of dynamic recrystallization. The alloy gains a finer grain structure by simultaneously promoting the formation and inhibiting the growth of recrystallized grains. As a result, the improvement in the overall mechanical properties of Al-Zn-Mg-Cu-Sc-Zr alloys brought about by the addition of Sc can be attributed primarily to the refinement of the initial as-cast grains, as well as fine-grain strengthening due to the inhibition of recrystallized grain growth and the Orovan strengthening of the nanoscale secondary phase Al3(Sc,Zr) itself.

Mechanical properties and toughening mechanism of B4C–Al2O3 composite ceramics prepared by hot-press sintering

Boron carbide-alumina (B4C–Al2O3) composite ceramics were fabricated using boron carbide (B4C) as the matrix and alumina (Al2O3) as the second phase by hot-press sintering at 1950 °C. The phase composition, microstructure, relative density, mechanical properties, and toughening mechanism of the composite ceramics were evaluated. When the content of Al2O3 is 30 wt%, the composite ceramics show the best comprehensive mechanical properties. The relative density, Vickers hardness, flexural strength, and fracture toughness of the obtained B4C-30 wt%Al2O3 composite ceramics reach up to 98.8 %, 24.7 GPa, 477 MPa, and 4.64 MPa m1/2, respectively. The introduction of Al2O3 as the second phase can significantly improve the fracture toughness of the B4C ceramics. Firstly, when cracks extend to the Al2O3 grains, the cleavage fracture of the Al2O3 grains resulting from its crystal structure causes the crack deflection along the cleavage plane. Secondly, due to the mismatch of the coefficient of thermal expansion between B4C and Al2O3, residual stress is generated at the grain boundary of the two phases and within the grains. The tensile stress at the grain boundary can cause some cracks to extend along the grain boundary, making cracks deflected, and the compressive stress within the B4C grains can inhibit crack extension. Thirdly, submicron-sized Al2O3 grains wrapped within the B4C grains form a subboundary structure, which can lead to crack extension along the subboundary. All of these factors consume the crack extension energy, which can contribute to increasing the fracture toughness of B4C–Al2O3 composite ceramics.

High-performance B4C-Al2O3 composite ceramics fabricated via fast hot-pressing sintering

In this study, fast hot-pressing sintering and the power of B4C and 1/3/5/7 wt% Al2O3 were used to make B4C-Al2O3 composite ceramics at 2000°C and 30 MPa. The toughening mechanism was thoroughly examined, and the impact of Al2O3 content on the microstructures and mechanical characteristics of B4C-Al2O3 composite ceramics was examined. The comprehensive mechanical properties of B4C-Al2O3 composite ceramics were optimized by adding 3 wt% Al2O3, the relative density, flexural strength, fracture toughness, and Vickers hardness reached 99.38%, 616.2 MPa, 5.45 MPa∙m1/2, and 35.91 GPa, respectively. The strengthening mechanism of B4C-Al2O3 composite ceramics is that grain refinement and grain boundary movement are hindered by second-phase particles. And the toughening mechanism is crack deflection and Al2O3 grain cracking.

Effects of duty cycle on microstructure and mechanical properties of (AlCrNbSiTi)N high-entropy nitride hard coatings deposited by pulsed arc ion plating

High entropy (AlCrNbSiTi)N hard coatings have been deposited by pulsed arc ion plating with various duty cycles. The effects of duty cycles on the morphology, chemical composition, microstructure and mechanical properties of coatings are studied. Higher duty cycles result in the increase of deposited particles and holes on the surface of the coatings. The coatings exhibited a single-phase face centered cubic structure with preferred orientation of (200). Appropriate duty cycle can significantly improve the comprehensive mechanical properties of the coatings. The coating exhibits highest hardness and elastic modulus of 43.4 GPa and 573.4 GPa, respectively. Formation of surface oxides during friction process are observed, which play a self-lubricating role.

Ultra-High-Performance Alkali-Activated Concrete: Effect of Waste Crumb Rubber Aggregate Proportions on Tensile and Flexural Properties

The declining availability of natural sand resources and the significant carbon footprint associated with the extensive use of cement are posing severe limitations on the advancement and application of ultra-high-performance concrete (UHPC). In this study, waste tyre-derived recycled crumb rubber particles (CR) were employed to replace quartz sand, and an alkali-activated cementitious material was used to produce waste tyre-alkali-activated UHPC (T-UHPAC). The influence of different CR replacement ratios (0%, 5%, 20%, 35%, 50%) on the tensile and flexural performance of T-UHPAC was investigated, and a predictive model for the stress–strain response considering the CR replacement ratio was established. An optimization method for improving the tensile and flexural performance of T-UHPAC was proposed. The results indicate that the effect of rough-surfaced CR on the interfacial properties of concrete differs from that of smooth quartz sand. A CR replacement ratio exceeding 35% led to a reduction in both the tensile and flexural strengths of UHPAC, while a replacement ratio at or below 20% resulted in a superior tensile and flexural performance of T-UHPAC. The established predictive model for tensile performance accurately forecasts the stress–strain behaviour of T-UHPAC under varying CR replacement ratios, with the accuracy improving as the CR replacement ratio increases. By utilizing CR to replace quartz sand in proportions not exceeding 20%, the production of low-carbon UHPC with exceptional comprehensive mechanical properties is achievable. Moreover, the development of T-UHPAC through the comprehensive utilization of waste tyres presents a promising and innovative approach for the low-carbon and cost-effective production of UHPC, thereby facilitating the sustainable development of natural resources. This research represents a significant step towards the widespread adoption and application of UHPC and thus holds substantial importance.

Effect of Multistage Solution Aging Heat Treatment on Mechanical Properties and Precipitated Phase Characteristics of High-Strength Toughened 7055 Alloy.

In this paper, a one-step hot extrusion dual-stage solution treatment method is employed to fabricate high-strength and tough T-shaped complex cross-section 7055 (Al-Zn-Mg-Cu-Zr) alloy profiles, and a detailed investigation is conducted on the microstructure and mechanical properties. The results indicate that the comprehensive mechanical properties of the 7055 aluminum extruded alloy using the two-stage solution aging treatment are excellent. This is particularly evident in the balance between strength and ductility, where outstanding strength is accompanied by a plasticity that is maintained at 13.2%. During the extrusion process, the deformation textures are mainly composed of brass and copper, forming a 15.1% recrystallization texture Cube. In addition, the equilibrium phase η(MgZn2) precipitated in the grain is the main strengthening phase, and there are large discontinuous grain boundary precipitates at the grain boundary, which hinders the grain boundary dislocation movement and has great influence on the mechanical properties of alloy materials.

Highly Durable Silicone-Based Elastomers Achieved Through the Synergy of Bi-Incompatible Soft Segments and Multi-Scale Hydrogen Bonds.

Developing a silicone elastomer with high strength, exceptional toughness, good crack tolerance, healability, and recyclability, poses significant challenges due to the inherent trade-offs between these properties. Herein, the design of silicone-based elastomers with a nanoscopic microphase separation structure and comprehensive mechanical properties is achieved by combining bi-incompatible soft segments and multi-scale hydrogen bonds. The formation of multi-scale hydrogen bonds involving urethane, urea, and 2-ureido-4[1H]-pyrimidinone (UPy) facilitates efficient reversible crosslinking of the synthesized polymer containing thermodynamically incompatible poly(dimethylsiloxane) (PDMS) and poly(propylene glycol) (PPG). The dynamic dissociation and recombination of hydrogen bonds, coupled with the forced compatibility and spontaneous separation of bi-incompatible soft segments, can effectively dissipate energy, particularly in the crack region during the stretching process. The obtained silicone-based elastomer exhibits a high break strength of 8.0 MPa, good elongation at break of 1910%, ultrahigh toughness of 67.8 MJ m-3, and unprecedented fracture energy of 31.8 kJ m-2 while maintaining their thermal stability, hydrophobicity, healability, and recyclability. This resilient and long-lasting silicone-based elastomer exhibits significant potential for use in flexible electronic devices.

The role of Ti in the phase transformation and microstructure manipulation of ZrCu alloys with excellent mechanical properties

The effect of Ti content on the phase composition, microstructure manipulation and work-hardening behavior of ZrCu alloys during compression was investigated in this work. The results show that the phase composition, microstructure, mechanical properties and work-hardening ability of ZrCu alloys are very sensitive to Ti content. The introduction of Ti enhances the stability of the austenite phase and the amorphous forming ability of ZrCu alloys. The Zr45Cu50Ti5 alloy exhibited best comprehensive mechanical properties, its yield strength, ultimate compressive strength and fracture strain are 981 MPa, 1922 MPa and 16.9%, respectively. Zr49Cu50Ti1 and Zr47Cu50Ti3 alloys have the best work hardening ability under low strain, and the Zr43Cu50Ti7 alloy has the best work hardening ability under high strain. Finally, the austenite stabilization mechanism, strengthening mechanism and work hardening mechanism are revealed.

Surface quality and mechanical property evolution of laser nitrided Zr-based metallic glass induced by laser shock flattening

Laser nitriding is an effective modification technique to improve the comprehensive mechanical properties of metallic glasses (MGs). However, numerous micro-defects, such as pores and humps, usually appear on the laser-nitriding-treated (LNed) MG surface, and therefore additional post-treatment is required. Herein, laser shock processing was implemented to flatten the LNed MG and as well modify its surface mechanical property. The dependence of the laser shock flattening process on the laser energy density was investigated. The results revealed that the surface micro-defects on the LNed MG were significantly reduced after laser shock flattening, and accordingly, the surface roughness (Sa) was decreased, with a maximum reduction of 61.87% (from 0.48 to 0.183 μm) achieved at a relatively high laser energy density of 178.3 J/cm2. Furthermore, nanoindentation measurements indicated that although the surface hardness of the LNed MG was decreased after laser shock flattening, it was still higher than that of the as-cast MG.

EFFECT OF A MAGNETIC FIELD ON THE MICROSTRUCTURE AND PROPERTIES OF RESISTANCE SPOT WELDED JOINTS OF 444 FERRITIC STAINLESS STEEL/6082 ALUMINUM ALLOY

To improve the welding quality of resistance spot welding joints of steel/aluminum lightweight structures, the steady magnetic field-assisted resistance spot welding method was used to weld 444 ferritic stainless steel and 6082 aluminum alloy, both with a thickness of 1 mm. Under the same welding parameters, the effect of a magnetic field on the microstructure and mechanical properties of the joint was analyzed. It was found that the Lorentz force generated by the addition of a magnetic field promoted the circumferential movement of the molten metal in the nugget zone, increased the size of the Fe/Al contact interface in the joint along the horizontal direction, and made an effective use of the heat generated during resistance spot welding. Although the intermetallic compounds in the intermediate transition layer of the two welded materials were mainly composed of (Fe, Cr, Si)Al2 and (Fe, Cr, Si)Al3, relatively low contents of (Fe, Cr, Si)Al2 and (Fe, Cr, Si)Al3 were found and a there was a significant decrease in the thickness of the intermetallic compound layer when the magnetic field was applied. Compared with the welded joint devoid of a magnetic field, the tensile strength and ductility of the joint were effectively improved, and the dimples in the fracture surface became relatively deep and numerous. In essence, resistance spot welding joints of steel/aluminum obtain better comprehensive mechanical properties when a magnetic field is applied.

Dual plate-like grains of (Ti, Zr)B2 and W2B5 toughened solid solution composites fabricated via in-situ reaction spark plasma sintering of (Ti, W)C and ZrB2 powders

Novel dual plate-like grains of (Ti, Zr)B2 and W2B5 toughened solid solution composites were fabricated by the in-situ reaction spark plasma sintering at 1800 °C using (Ti, W)C and ZrB2 powders. The composites were predominated and composed of the (Zr, Ti, W)C solid solutions and plate-like (Ti, Zr)B2. In the (Ti, W)C-ZrB2 reaction system, W promotes the anisotropic growth of (Ti, Zr)B2 grains, while Ti makes the formation reactions of WxBy thermodynamically feasible. When the addition of ZrB2 exceeds 40 mol%, W begins to be boronized into WxBy which is mainly composed of plate-like W2B5. The (Ti, W)C-50 mol% ZrB2 composite with dual plate-like grains of (Ti, Zr)B2 and W2B5 exhibited the best comprehensive mechanical properties of hardness of 26.5 GPa, flexural strength of 620 MPa, and fracture toughness of 6.6 MPa·m1/2, which provide a new approach for the enhanced toughness without the introducing of metal impurities.

Fabrication and improved properties of ZrC-SiC-ZrB2 ceramics by ultra-high pressure sintering

ZrC-SiC-ZrB2 ceramics were prepared via ultra-high pressure sintering under 15 GPa at 1200 °C. The densification mechanism, microstructures, and properties of the prepared ceramics were investigated. The sintered ceramics with ZrB2 content of 15 vol% showed the improved comprehensive mechanical properties, including Vickers hardness of 26.6 GPa, Young's modulus of 469.1 GPa, and fracture toughness of 5.0 MPa·m1/2, which was 86.7% higher than that of pure ZrC ceramics. In the sintered sample, the ultra-high pressure induced new microstructure, such as L-C lock in ZrC phase, stacking faults and nanotwins in SiC phase, and severe lattice distortion in ZrB2 phase, jointly contributed to the improvement in Vickers hardness. Deflection and bridging during crack propagation were ascribed to the uniform combination of various phases.

Preparation, Characterization, and Bioactivities of Cobalt, Strontium and Fluorine Co-Doped Oxide Films on Titanium Surface for Clinical Application

Titanium and titanium alloys are receiving widespread attention due to their excellent comprehensive mechanical properties, corrosion resistances, and biocompatibilities. However, titanium metal itself is biologically inert in physiological environments, and after implantation, it is surrounded by a layer of encapsulating fibrous membrane, making it difficult to form solid bonds with the tissue. Plasma electrolytic oxidation is a new technology used to prepare bioactive porous ceramic membranes on the surfaces of titanium and titanium alloys. It has application prospects for biomimetic surface modifications of titanium alloys. In this study, a cobalt, strontium and fluorine codoped oxide film (TAM-CSF) was prepared on a titanium surface via plasma electrolytic oxidation. The surface characteristics of the film were evaluated with field emission scanning electron microscopy, energy spectrum analyses, atomic force microscopy, profilometry and X-ray photoelectron spectroscopy. Additionally, the corrosion performance of the material was evaluated with an electrochemical workstation. The biocompatibility and bioactivity of the film were tested with in vitro cell experiments. The results showed that the TAM-CSF on the titanium surface had a porous morphology, and the CSF was uniformly doped on the film surface. TAM-CSF improved the surface roughness of the titanium. This film exhibited good biocompatibility and promoted the extension and proliferation of MC3T3-E1 cells. It was possible to prepare TAM-CSF on titanium surfaces via plasma electrolytic oxidation. The film exhibited a good morphology and good biological activity and has clinical application prospects.

Effect on microstructure and mechanical properties of friction stir welded 5A06 aluminum alloy joints by deep cryogenic treatment

In order to improve the comprehensive mechanical properties of the welded joints of the 5A06 aluminum alloy, friction stir welded (FSW) joints were subjected to deep cryogenic treatment (DCT). The microstructure and mechanical properties were characterised using metallographic microscopy, x-ray diffractometer (XRD), energy spectrometer, microhardness tests, and tensile tests. The experimental results show that DCT refines the structure significantly due to the large temperature difference. This refinement results from an increase in Mg atoms within the α-Al solid solution through the precipitation of Al atoms, forming the Al3Mg2 phase. This enhancement in plasticity is achieved through dispersion distribution. Moreover, as the treatment time of DCT increases, the mechanical properties of the welded joint also improve significantly. The microhardness of the welding joint peaked at DCT3h, rising from 78.8 HV at DCT0h to 87.2 HV at DCT3h. Meanwhile, the tensile strength of the joint reached its maximum at DCT12h, rising from 358.7 MPa at DC0h to 385.3 MPa at DCT12h, representing a 7.4% increase. These experimental results underscore the significant impact of DCT on improving the welded joints.

Hot deformation behavior and extrusion temperature-dependent microstructure, texture and mechanical properties of Mg–1Mn alloy

Mg–1Mn alloy, extruded at a low temperature in our published protocol, contributed to the intensified basal texture and extremely refined microstructure with spheroidal nanoscale precipitates dispersing throughout the matrix and along the grain boundaries, consequently resulting in the excellent mechanical properties where the alloy exhibited a tensile yield strength of 204.3 MPa and a ductility of 38.8% at room temperature. Therefore, Mg–1Mn alloy was recommended as one of the potential materials for structural applications. In the present investigation, hot deformation behavior through constitutive analysis and extrusion temperature-dependent microstructure, texture and mechanical properties of as-extruded Mg–1Mn alloy were investigated, aiming at revealing how extrusion temperature affected microstructure, texture, and mechanical properties of as-extruded Mg–1Mn alloy. X-ray diffraction patterns demonstrated that phase components of the experimental alloys consisted of the α-Mg matrix and Mn precipitates. Optical microscopy images indicated a significant increase in average grain size of the alloys as the extrusion temperature increasing from 250 °C to 400 °C. Scanning electron microscopy graphics revealed that coarsened particles identified as Mn precipitates by EDS were observed within the matrix when extrusion temperature reached 400 °C. Inverse pole figure maps of the experimental samples subjected to different extrusion temperatures in the present work exhibited the typical basal texture, suggesting that basal slip was activated hardly during the tensile stress applied along the extrusion direction. Consequently, extrusion temperature displayed the significant impact on microstructure, texture, and mechanical properties of as-extruded Mg–1Mn alloy. The alloy extruded at both 250 °C and 300 °C exhibited the strong basal texture and refined microstructure with spheroidal nanoscale precipitates dispersing within the matrix and along the grain boundaries, which contributed to their excellent comprehensive mechanical properties. The alloy extruded at 400 °C possessed the typical basal texture and coarsened microstructure, leading to the extremely poor mechanical properties. Simultaneously, the constitutive model of the Arrhenius equation based on Zener-Hollomon parameters was also established in the present investigation. Therefore, optimizing the extrusion temperature to regulate the microstructure, grain orientation distribution, and morphology of precipitates was considered as one of the effective approaches for achieving the excellent mechanical properties of Mg alloys.

The synthesis and research of a novel organosilicon-modified waterborne blocked polyisocyanate crosslinker with a semi-interpenetrating network structure

The organosilicon intermediate containing hydrophilic tertiary amines was synthesized from N-Methylmonoethanolamine (MEA) and (3-glycidyloxypropyl) trimethoxy silane (GPTMS), followed by neutralization with acetic acid (Ac). Meanwhile, a polyurethane (PU) prepolymer was prepared by sequentially polymerizing hexamethylene diisocyanate trimer (HT-100) with polyethylene glycol (PEG-600) and methoxy polyethylene glycol (MPEG), and then chain extended by the intermediate. Ultimately, methyl ethyl ketone oxime (MEKO) was selected to block the remaining NCO group, forming a branched polyisocyanate crosslinker. Subsequently, a linear polyisocyanate crosslinker was prepared in the same system by polymerizing hexamethylene diisocyanate (HDI) with the intermediate. Consequently, an organosilicon-modified waterborne blocked polyisocyanate crosslinker with a semi-interpenetrating network structure was obtained and further processed through hydrolysis to obtain the corresponding crosslinker containing silanol groups. The structure and thermal properties of the crosslinkers were analyzed using 1H NMR, FT-IR, TG, and DTG. Furthermore, the comprehensive mechanical properties of the cured films were investigated. The results indicate that the crosslinker system containing silanol groups exhibits superior performance. When the films' maximum adhesion and the wiping resistance were optimized at 1.97 MPa and 72 times, respectively, the impact resistance still maintained above 85 cm.

The role of Si in enhancing the stability of residual austenite and mechanical properties of a medium carbon bainitic steel

In this work, two bainitic steels with medium carbon content were developed by adding different Si. The mechanical properties of the two test steels and the stability of their retained austenite were studied, and the influence of Si in the steels was discussed. The results show that the film-like retained austenite of the high Si bainitic steel is greatly increased compared with that of the low Si bainitic steel and that the C content is increased, effectively preventing crack propagation and significantly improving the comprehensive mechanical properties. Due to the different Si content in the test steels, the orientation relationship of austenite in the steels has changed, and when the Si content is increased from 0.7 wt% to 1.4 wt%, the variant selection of bainite becomes weaker. Moreover, the increase of Si content not only inhibits the precipitation of carbides but also promotes the accumulation of C in the austenite, which improves the stability of the retained austenite.

Effects of Mo content on the microstructure and mechanical properties of laser cladded FeCoCrNiMox (x = 0.2, 0.5) high-entropy alloy coatings

The laser cladding additive manufacturing technology and high-entropy alloys can serve as ideal techniques and materials for the surface repair of high-speed train axles. Coatings of FeCoCrNiMox (x = 0.2, 0.5) were prepared on EA4T axle steel using laser cladding technology, and their phase, structure, and mechanical properties were analyzed using X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and electron channeling contrast imaging (ECCI) characterization techniques. Additionally, the mechanical properties of the coatings were tested, and first-principles calculations were used to verify and calculate the material's mechanical performance. The research findings indicate that an increase in Mo content leads to a greater degree of lattice distortion, causing a leftward shift in diffraction peak positions. Significant differences in the microstructure from the substrate to the coating surface were observed, with columnar grain structure at the bottom of the cladding layer and equiaxed dendrites dominating the coating surface. The increase in Mo content promotes the formation of σ phase while also refining the grain size. ECCI results show that both types of coatings consist of a high-density dislocation cell structure and Mo-rich particles. With an increase in Mo content, the peak hardness of the coating increased from 456.5 HV to 469.4 HV, while the impact energy decreased from 56 J to 16 J, attributed to the increase in dislocation density and the greater quantity of σ phase. First principles calculations verified that the comprehensive mechanical properties of FeCoCrNiMo0.2 are superior, providing theoretical guidance for the optimization and design of the coatings.