Tribological Property of Ni<Subscript>3</Subscript>Al Matrix Composites with Addition of BaMoO<Subscript>4</Subscript>

The Ni₃Al matrix composites with addition of 10, 15, and 20 wt% BaMoO₄ were fabricated by powder metallurgy technique, and the tribological behaviors were studied from room temperature to 800 °C. It was found that BaAl₂O₄ formed during the fabrication process. The Ni₃Al composites showed poor tribological property below 400 °C, with high friction coefficients (above 0.6) and wear rates (above 10⁻⁴ mm³/Nm). However, the composites exhibited excellent self-lubricating and anti-wear properties at higher temperatures, and the composite with addition of 15 wt% BaMoO₄ had the lowest wear rate (1.10 × 10⁻⁵ mm³/Nm) and friction coefficient (0.26). In addition, the results also indicated that BaAl₂O₄ for the Ni₃Al composites did not exhibit lubricating property from room temperature to 800 °C.     

High Wear Resistance of Magnetron Sputtered Cr<Subscript>80</Subscript>Si<Subscript>20</Subscript>N Nanocomposite Coatings: Almost Independent of Hardness

Hardness has been popularly considered as an essential factor defining the wear resistance of hard coatings. Here, we report magnetron sputtered Cr₈₀Si₂₀N nanocomposite coatings, of widely varied packing densities, that exhibited identical specific wear rates, while the hardness changed over a wide range (from ~12 to ~36 GPa). All the Cr₈₀Si₂₀N coatings were free of extended and uninterrupted columnar boundaries, and retained low specific wear rates in the ball-on-plate sliding tests against Al₂O₃ counterpart with a normal load of 5 N (less than 3.0?×?10^?16 m³/N m under ambient condition and less than 2.0?×?10^?15 m³/N m under 3.5 wt% NaCl solution, respectively). Post examination reveals extensive interruption or termination of cracks in the wear tracks of the under-dense coatings, indicative of extrinsic toughening mechanisms by effective relief of local contact stress. Our results suggest that a critical role of toughening rather than hardening, played in enhancing the wear resistance of hard coatings, and thus would pave a way to develop highly wear-resistant coatings with a low hardness.     

Synergistic Effect of Nano-MoS<Subscript>2</Subscript> and Anatase Nano-TiO<Subscript>2</Subscript> on the Lubrication Properties of MoS<Subscript>2</Subscript>/TiO<Subscript>2</Subscript> Nano-Clusters

A MoS₃ precursor deposited on anatase nano-TiO₂ is heated at 450 °C in an H₂ atmosphere to synthesize MoS₂/TiO₂ nano-clusters. The nano-clusters are then characterized, and their tribological properties are evaluated. MoS₂ is found to be composed of layered structures with 1–10 nm thicknesses, 10–30 nm lengths, and 0.63–0.66 nm layer distances. The MoS₂ sizes in the MoS₂/TiO₂ nano-clusters are smaller and their layer distances are larger than those of pure nano-MoS₂. The MoS₂/TiO₂ nano-clusters also present a lower average friction coefficient than pure nano-MoS₂, but the anti-wear properties of both the nano-clusters and pure nano-MoS₂ are similar. X-ray photoelectron spectroscopy indicates that nano-TiO₂ and the element Mo are transferred to the friction surface from the MoS₂/TiO₂ nano-clusters through a tribochemical reaction. This produces a lubrication film containing TiO₂, MoO₃, and other chemicals. The nano-MoS₂ changes in size and layer distance when combined with nano-TiO₂, producing a synergistic effect. This may further be explained using a micro-cooperation model between MoS₂ nano-platelets and TiO₂ solid nanoparticles.     

Study on the Synthesis and Tribological Property of Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> Based Magnetic Fluids

In this paper, Fe₃O₄ based magnetic fluids with different particle concentrations were prepared by the co-precipitation technique. The size of the Fe₃O₄ nanoparticles is about 13 nm and their shape is spherical. The tribological performances of the fluids with different concentration Fe₃O₄ nanoparticles were evaluated in a MMW-1A four-ball machine. The results show that the tribological performance of magnetic fluids with proper Fe₃O₄ nanoparticles can be improved significantly. The maximum nonseized load (P _B) has been increased by 38.4% compared with carrier liquid. The wear scar diameter has been reduced from 0.68 mm to 0.53 mm and the relative percentage in friction coefficient has decreased to 31.3%. The optimal concentration of the Fe₃O₄ nanoparticles in the carrier liquid is about 4 wt.%.     

Fullerene-like MoS<Subscript>2</Subscript> Nanoparticles and Their Tribological Behavior

Using a new quartz-made reactor, large amounts of fullerene-like (IF) MoS₂ nanoparticles were synthesized by reacting MoO₃ vapor with H₂S in a reducing atmosphere. The nanoparticles were found to be of high crystalline order; with an average size of 70 nm and consist of more than 30 closed shells. Extensive tribological testing of the nanoparticles in two types of synthetic oils- poly-alpha olefins (PAO)- was carried out and compared to that of bulk (2H platelets) MoS₂ and IF-WS₂. These tests indicated that under high pressure and relatively low humidity, the IF-MoS₂ exhibited a friction coefficient as low as 0.03 and the smallest wear rate of the measured systems. However, its performance was found to be lower in comparison to IF-WS₂ after 2500 cycles, due probably to its inferior chemical stability. This study indicates that the tribological performance of the IF nanoparticles depends strongly on their crystalline order and size.     

Cutting performance of Si<Subscript>3</Subscript>N<Subscript>4</Subscript>/TiC micro-nanocomposite ceramic tool in dry machining of hardened steel

A type of Si₃N₄/TiC micro-nanocomposite ceramic cutting tool material was fabricated using Si₃N₄ micro-matrix with Si₃N₄ and TiC nanoparticles. Cutting performance of the Si₃N₄/TiC ceramic cutting tool in dry cutting of hardened steel was investigated in comparison with a commercial Sialon insert. Hard turning experiments were carried out at three different cutting speeds, namely 97, 114, and 156 m/min. Feed rate (f) and depth of cut (a _p) were fixed at 0.1 mm/rev and 0.2 mm, respectively. Results showed that cutting temperature increased rapidly to nearly 1000 °C with increasing cutting speed. The two types of cutting tools featured similar wear behavior. However, the Si₃N₄/TiC micro-nanocomposite ceramic cutting tool exhibited better wear resistance than the Sialon tool. Morphologies of crater and flank wear were observed with a scanning electron microscope. Results indicated that wear variation of the two types of ceramic cutting tools differed in the same conditions. Wear of the Si₃N₄/TiC micro-nanocomposite ceramic cutting tool is mainly dominated by abrasion and adhesion, whereas that of the Sialon ceramic cutting tool is dominated by abrasion, adhesion, thermal shock cracking, and flaking.     

Wear Behaviour of In Situ Al/TiB<Subscript>2</Subscript> Composite: Influence of the Microstructural Instability

In this present work, the in situ Al (A380)/5 wt%TiB₂ composites were fabricated through salt–melt reaction using halide salts such as potassium hexafluorotitanate (K₂TiF₆) and potassium tetra fluoroborate (KBF₄) salts as precursors. The composites were produced at four different melt temperatures (700, 750, 800, 850 °C). The formation of particle was confirmed from XRD results. The wear behaviour of Al/5 wt% TiB₂ composite was investigated by varying the wear test parameters such as sliding temperature (25, 100, 150, 200 °C), applied load (10, 20, 30, 40 N), sliding velocity (0.4, 0.7, 1, 1.3 m/s). The microstructure of Al/5 wt% TiB₂ composite was correlated with the wear characteristics of the composites. The wear resistance of Al/5 wt% TiB₂ composite was significantly improved due to the presence of TiB₂ particle in Al matrix material. The composite produced at melt temperature 800 °C showed a higher wear resistance at applied load: 10 N, sliding temperature: 25 °C and sliding velocity: 0.7 m/s. The wear mechanism for each of the tested condition was identified from the worn surfaces using scanning electron microscopy (SEM). ANOVA test was carried out to find out significant factor for the wear resistance of composite. The checking of adequacy of experimental value for the wear behaviour of composite for different testing condition was analysed by residual plots using statistical software.     

Abrasive and Adhesive Wear Behavior of Arc-Evaporated Al<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>Cr<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>N Hard Coatings

During the last decade, the usage of difficult-to-machine materials such as austenitic stainless steels has increased continuously in various industrial applications. Tools such as blind hole taps, punches, or deep drawing molds are often exposed to severe wear while machining/forming these materials, mainly due to excessive adhesion and material transfer. On combination with abrasive wear due to work-hardened wear debris, tool lifetime in these applications is often limited. In this study, ball-on-disc experiments were carried out with arc-evaporated AlCrN coatings with different Al/(Al + Cr) ratios against Al₂O₃ and austenitic stainless steel balls in ambient atmosphere. Test temperatures of 25, 500, and 700°C were chosen for the hard Al₂O₃ balls simulating severe abrasive loads, whereas 25, 150, and 250°C were used for the softer stainless steel material to evaluate the adhesive wear behavior. Characterization of the wear tracks was done by scanning electron microscopy in combination with energy-dispersive X-ray analysis and optical profilometry. The best abrasive wear resistance during testing against Al₂O₃ was observed for the coating with the highest Al content. In the case of the austenitic stainless steel balls, sticking of the ball material to the coating surface was the dominating wear mechanism. The influence of test temperature, chemical composition, and surface roughness was studied in detail.     

Synergistically toughening effect of SiC whiskers and nanoparticles in Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-based composite ceramic cutting tool material

In recent decades, many additives with different characteristics have been applied to strengthen and toughen Al₂O₃-based ceramic cutting tool materials. Among them, SiC whiskers and SiC nanoparticles showed excellent performance in improving the material properties. While no attempts have been made to add SiC whiskers and SiC nanoparticles together into the ceramic matrix and the synergistically toughening effects of them have not been studied. An Al₂O₃-SiC_w-SiC_np advanced ceramic cutting tool material is fabricated by adding both one-dimensional SiC whiskers and zero-dimensional SiC nanoparticles into the Al₂O₃ matrix with an effective dispersing and mixing process. The composites with 25 vol% SiC whiskers and 25 vol% SiC nanoparticles alone are also investegated for comparison purposes. Results show that the Al₂O₃-SiC_w-SiC_np composite with both 20 vol% SiC whiskers and 5 vol% SiC nanoparticles additives have much improved mechanical properties. The flexural strength of Al₂O₃-SiC_w-SiC_np is 730±95 MPa and fracture toughness is 5.6±0.6 MPa·m^1/2. The toughening and strengthening mechanisms of SiC whiskers and nanoparticles are studied when they are added either individually or in combination. It is indicated that when SiC whiskers and nanoparticles are added together, the grains are further refined and homogenized, so that the microstructure and fracture mode ratio is modified. The SiC nanoparticles are found helpful to enhance the toughening effects of the SiC whiskers. The proposed research helps to enrich the types of ceramic cutting tool and is benefit to expand the application range of ceramic cutting tool.     

Mechanical properties and tribological behavior of ZrO<Subscript>2</Subscript> thin films deposited on sulfonated self-assembled monolayer of 3-mercaptopropyl trimethoxysilane

A silane coupling reagent (3-mercaptopropyl)trimethoxysilane (abridged as MPTS) was self-assembled on a single-crystal Si substrate to form a two-dimensional organic monolayer (MPTS-SAM). The terminal –SH group in the MPTS-SAM film was in-situ oxidized to –SO₃H group to endow the film with good chemisorption ability. Then ZrO₂ thin films were deposited on the oxidized MPTS-SAM by way of the enhanced hydrolysis of aqueous zirconium sulfate (Zr(SO₄)₂·4H₂O) in the presence of aqueous HCl at 50 °C, making use of the chemisorption ability of the –SO₃H group. The thickness of the ZrO₂ films was determined with an ellipsometer, while their morphologies and corresponding friction forces were analyzed by means of atomic force microscopy. The hardness and elastic modulus of the ZrO₂ thin films were determined on a Nanoindentation II (MET) instrument. The macro-friction and wear behaviors of the ZrO₂ films sliding against an AISI-52100 steel ball were examined on a unidirectional friction and wear tester and the worn surface morphologies observed on a scanning electron microscope (SEM). As the results, the as-deposited ZrO₂ thin film at a deposition duration of 100 h is about 100 nm thick, it decreases to 48 nm after annealing at 500 °C and further decreases to 45 nm after heating at 800 °C. The as-deposited ZrO₂ film is relatively rougher, with the rms to be about 1.0 nm, while the ZrO₂ thin films heated at 500 and 800 °C have surface roughness rms of 0.76 nm and 0.68 nm, respectively. The ZrO₂ film annealed at 800 °C has a high hardness to elastic modulus (H/E) ratio (0.062) as compared to the as-deposited ZrO₂ film and the film annealed at 500 °C. Both the two annealed ZrO₂ films show excellent wear-resistance as they slide against AISI-52100 steel at a normal load below 2.0 N, while the one annealed at 800 °C has better wear-resistance. The differences in the friction and wear behaviors of the as-deposited ZrO₂ film, the ZrO₂ film annealed at 500 °C and that annealed at 800 °C are attributed to their different micro structures and compositions. Since the ZrO₂ films was well adhered to the underlying MPTS-SAM, it might find promising application in the surface-protection of single crystal Si and SiC subject to sliding at small normal load in microelectromechanical systems (MEMS).     

Effects of silica addition on the particle characteristics and phase transition of flame-synthesized γ-Al2O3 nanoparticles

The effects of silica addition on the thermal stability of flame-synthesized γ-Al₂O₃ nanoparticles are investigated in this study. Based on the electron microscope images of pure alumina, nanoparticles with diameters ranging from 20 nm to 30 nm were synthesized. No significant changes were observed after heat treatment at 900°C, 1100°C, and 1180°C. After heat treatment at 1260°C, sintered particles larger than 100 nm were observed. All images of the nanoparticles doped with silica, including those taken after heat treatment at 1260°C, showed similar particle sizes regardless of treatment temperature. Based on the X-ray diffraction patterns and specific surface areas, the onset temperature of the phase transition to α-Al₂O₃ for the flame-synthesized pure alumina was near 1180°C. The addition of silica greatly increased the thermal stability of the synthesized γ-Al₂O₃ nanoparticles.     

Effect of Applied Load and Surface Roughness on the Tribological Properties of Ni-Based Superalloys Versus Ta<Subscript>2</Subscript>AlC/Ag or Cr<Subscript>2</Subscript>AlC/Ag Composites

The novel Ta₂AlC–20 vol.% Ag (TaAg) and Cr₂AlC–20 vol.% Ag (CrAg) composites were tribologically tested versus a Ni-based superalloy Inc718 (SA) by dry sliding at a sliding speed of 1 m/s at room temperature in air at loads from 3 N to 18 N. The TaAg composites were also tested at 8 and 18 N at 550 °C, and at a 3 N load against the SA with different surface roughnesses at 26 °C and 550 °C. At room temperatures, the coefficients of friction, μ’s, decreased from ~0.8–0.9 to ~0.3–0.4 for both the TaAg and CrAg composites as the applied normal force increased from 3 N to 8 N. Further increases in load to 18 N did not change the μ’s. The specific wear rates, sWR, increased with increased loads for the TaAg composite; they remained almost unchanged for the CrAg composite. This behavior was attributed to the formation of glaze tribofilms—similar to ones observed previously in these tribocouples at elevated temperatures and 3 N—promoted by the increased loads. Preconditioning of the SA surface by sliding against the TaAg composite at 550 °C and 8 N resulted in μ’s of <0.2 and sWR < 10⁻⁶ mm³/N-m in subsequent room temperature sliding at 3 N. Somewhat higher, but stable room temperature μ’s of ~0.3 and sWR of ~3 × 10⁻⁵ mm³/N-m were observed when the TaAg composites were slid versus a sandblasted SA surface at 500 °C and 3 N. It follows that in situ preconditioning of the tribo-surfaces is a powerful tool for improving the properties of the MAX/Ag-SA tribocouples. The relationship between sliding conditions, chemistries of tribofilms, and their properties are discussed.     

Effect of Atmosphere and Temperature on the Tribological Behavior of the Ti Containing MoS<Subscript>2</Subscript> Coatings Against Aluminum

MoS₂ coatings exhibit low coefficient of friction (COF) when sliding against aluminum; however, the magnitudes of their COF show high sensitivity to environmental conditions. Ti could reduce the sensitivity of the frictional behavior of MoS₂ coatings to moisture. This study examines the tribological properties of Ti containing MoS₂ coating (Ti–MoS₂) tested against an aluminum alloy (Al-6.5% Si) in ambient air (58% relative humidity, RH), dry oxygen, dry air and dry N₂ (< 4% RH) atmospheres. The Ti–MoS₂ coating exhibited similar COF values under an ambient (0.14), dry oxygen (0.15) and dry air (0.16) atmospheres. It was found that oxidation of MoS₂ to MoO₃ was responsible for high COF under these testing conditions as revealed by Energy-dispersive X-ray Spectroscopy (EDS) and micro-Raman spectroscopy. However, a low and stable COF of 0.07 was observed under a dry N₂ condition. This work further showed that the tests performed at elevated temperatures, up to 400 °C in a dry N₂ atmosphere sustained the low and stable COF of the Ti–MoS₂ coatings. The sliding tests performed under a dry N₂ atmosphere prevented the formation of MoO₃ and as a result, the Ti–MoS₂ coatings maintained low COF values. Low COF values were also attributed to the formation of MoS₂ transfer layers.     

Tribological behaviors and mechanisms of Ti<Subscript>3</Subscript>AlC<Subscript>2</Subscript>

Tribological behaviors and the relevant mechanism of a highly pure polycrystalline bulk Ti₃AlC₂ sliding dryly against a low carbon steel disk were investigated. The tribological tests were carried out using a block-on-disk type high-speed friction tester, at the sliding speeds of 20–60 m/s under a normal pressure of 0.8 MPa. The results showed that the friction coefficient is as low as 0.1∼0.14 and the wear rate of Ti₃AlC₂ is only (2.3–2.5) × 10⁻⁶ mm³/Nm in the sliding speed range of 20–60 m/s. Such unusual friction and wear properties were confirmed to be dependant dominantly upon the presence of a frictional oxide film consisting of amorphous Ti, Al, and Fe oxides on the friction surfaces. The oxide film is in a fused state during the sliding friction at a fused temperature of 238–324 °C, so it takes a significant self-lubricating effect.     

Dry-Blasting of α- and κ-Al2O3 CVD Hard Coatings: Friction Behaviour and Thermal Stress Relaxation

Post-deposition blasting treatments of cemented carbide cutting tools coated by chemical vapour deposition have gained increasing interest. Within the present work, α- and κ-Al₂O₃ coatings dry-blasted using different pressures as well as globular and edged blasting materials were investigated. A higher pressure resulted in an increase in the compressive residual stresses, as determined by X-ray diffraction. Both blasting materials had a minor influence on the roughness of α-Al₂O₃, while the edged material caused a significant roughness increase for κ-Al₂O₃. For α-Al₂O₃ dry-blasted using the globular material, complete stress relaxation could be observed after annealing at 500 °C, whereas for α-Al₂O₃ dry-blasted using the edged material as well as for the κ-Al₂O₃, an annealing temperature of 900 °C was necessary for stress relaxation. The friction coefficient of the dry-blasted samples first increases with increasing temperature, due to increasing plastic deformation of the blasting material transferred onto the coating surface, until it decreases again above 700 °C, due to softening of the transferred material.     

Tribological Properties and Wear Mechanisms of NiCr–Al2O3–SrSO4–Ag Self-Lubricating Composites at Elevated Temperatures

NiCr–Al₂O₃–SrSO₄–Ag self-lubricating composites were prepared by powder metallurgy method and the tribological properties of composites were evaluated by a ball-on-disk tribometer against alumina ball at wide temperature range from the room temperature to 1,000 °C in air. The linear coefficient of thermal expansion was evaluated for investigation of thermal stability of composites. The tribo-chemical reaction films formed on the rubbing surfaces and their effects on the tribological properties of composites at different temperatures were addressed according to the surface characterization by SEM, XRD, and XPS. The results show that the NiCr–Al₂O₃ composite with addition of 10 wt% SrSO₄ and 10 wt% Ag exhibits satisfying friction and wear properties over the entire temperature range from room temperature to 1,000 °C. The composition of the tribo-layers on the worn surfaces of the composites is varied at different temperatures. The synergistic lubricating effect of SrAl₄O₇, Ag, and NiCr₂O₄ lubricating films formed on worn surfaces were identified to reduce the friction coefficient and wear rate from room temperature to 800 °C. Meanwhile, at 1,000 °C, the SrCrO₄ and NiAl₂O₄ was formed on the worn surfaces during sliding process, combining with the NiCr₂O₄, Al₂O₃, Cr₂O₃, Ag, and Ag₂O, which play an important role in the formation of a continuous lubricating film on the sliding surface.     

Wear Resistance of the La<Subscript>62</Subscript>Cu<Subscript>12</Subscript>Ni<Subscript>12</Subscript>Al<Subscript>14</Subscript> Bulk Metallic Glass Under Dry Friction Conditions

The wear properties of a La₆₂Cu₁₂Ni₁₂Al₁₄ bulk metallic glass (BMG) using sliding wear system under the various normal loads and the annealing conditions have been investigated. Although the La₆₂Cu₁₂Ni₁₂Al₁₄ BMG is brittle during the tensile testing, it exhibits ductile behaviors during the sliding wear process. The SEM and the EDS analyses of the wear tracks and the debris after the sliding wear processes indicate that the wear mechanism is a combination of abrasion, adhesion, and oxidation. It is found that the wear resistance is significantly affected by the normal loads. With the increases in the wear load, the wear loss and the friction coefficient decrease. In addition, it is found that the wear properties are significantly affected by the annealing conditions. Compared with the annealed BMG alloys, the as-cast BMG alloy with a low hardness exhibits good wear resistance, which is attributed to the better ductility during the wear testing.     

Tribological Properties of New MoS2 Nanoparticles Prepared by Seed-Assisted Solution Technique

Seed-assisted solution synthesis of hollow IF-MoS₂ nanoparticles allows independent control of particles size and MoS₂ slabs crystallinity. Variations of the reaction mixture composition influence the particle size in the range 50–150 nm. As demonstrated by Rietvelt refinement of the X-ray diffraction patterns, the sulfide crystallinity depends only on the post-treatment temperature (350–750 °C) and not on the particle size. The tribological properties of new MoS₂ nanoparticles prepared by seed-assisted solution technique were investigated and showed a strong decrease in the friction coefficient and wear compared with base oil. Small particles of 50–60-nm size showed the best results. The particle size above 100 nm is deleterious for the lubrication properties since it hinders particles penetration into the contact zone. MoS₂ slabs crystallinity had lesser influence on the lubrication efficiency. However, less-crystallized samples treated at 350 °C showed better lubrication, apparently because of easier exfoliation of the individual MoS₂ slabs, leading to more efficient formation of tribofilm.     

Measuring the light yield in a CaMoO<Subscript>4</Subscript> scintillating crystal

The light yield in CaMoO₄ scintillating crystals irradiated with α particles and γ rays from ²⁴¹Am and ¹³⁷Cs radioactive isotopes, respectively, have been measured. It is shown that the light yield in this crystal for γ rays, measured in the wavelength range of 400–700 nm at room temperature (22°C), is ～3000 photons/MeV, and the ratio α/β is ～0.25.     

Microstructure,chemical composition,wear, and corrosion resistance of FeB–Fe<Subscript>2</Subscript>B–Fe<Subscript>3</Subscript>B surface layers produced on Vanadis-6 steel using CO<Subscript>2</Subscript> laser

The paper presents the study results of laser modification of FeB–Fe₂B surface layers produced on Vanadis-6 steel using pack cementation method. Microstructure, x-ray phase analysis, chemical composition study using wave dispersive spectrometry method, microhardness, corrosion resistance as well as surface condition, roughness, and wear resistance were investigated. The diffusion boronizing processes were performed at 900 °C for 5 h in the EKabor® powder mixture. The boronized layers had a dual-phase microstructure composed of two types of iron borides, FeB and Fe₂B, and their microhardness ranged from 1800 to 1400 HV. The laser surface modification was carried out on specimens after diffusion boronizing process using CO₂ laser with a nominal power of 2600 W. Laser beam power used in this experiment was equal to 1040 W and was constant. While the three values of scanning speed were used: 19, 48, and 75 mm/s. During laser modification, the multiple tracks were made where distance between of axis tracks was equal to 0.5 mm. As a result of this process, microstructure consisted of remelted zone, heat-affected zone, and substrate was obtained. In remelted zone, the boron-martensite eutectic was observed. Boronized layers after laser modification were characterized by the mild gradient of microhardness from surface to the substrate and their value was dependent on the scanning speed used and was between 1700 and 1100 HV. Corrosion resistance tests revealed reducing the current of corrosion in case of laser modification process. Wear resistance of laser modified specimens was improved in comparison to diffusion boronized layers.