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Khalil Abdelrazek Khalil - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and densification of nanostructured Al2O3-(ZrO2+3%Mol Y2O3) bioceramics by high-frequency Induction Heat sintering
Materials Science Forum, 2020Co-Authors: Khalil Abdelrazek KhalilAbstract:Nanostructured Alumina – 20 vol% 3YSZ composites powder were synthesized by wetmilling technique. The starting materials were a mixture of Alumina micro-powder and 3YSZ nano-powders. Nano-crystalline grains were obtained after 24 h milling time. The nano-structured powder compacts were then processed to full density at different temperatures by high-frequency Induction Heat sintering (HFIHS). Effects of temperature on the mechanical and microstructure properties have been studied. Al2O3-3YSZ composites with higher mechanical properties and small grain size were successfully developed at relatively low temperatures through this technique. The samples were densified by Heating to a sintering temperature in the range of 1100 to 1400 °C, and then fast cooled to 500 °C within short time. A relative density of up to 99% theoretical density of the composites was achieved after sintering at 1370 °C.
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Observation of Toughness Improvement of the Hydroxyapatite Bioceramics Densified Using High-Frequency Induction Heat Sintering
International Journal of Applied Ceramic Technology, 2020Co-Authors: Khalil Abdelrazek KhalilAbstract:A novel nanocomposite has been introduced to improve the fracture toughness of hydroxyapatite (HAp) bioceramics. Composites of HAp/NiO with 1–5 wt% of electrospun NiO nanofibers were developed and studied. The mixtures were consolidated very rapidly to full density by high-frequency Induction Heat sintering (HFIHS). The role of NiO nanofibers in enhancing the toughness, hardness, and microstructure properties of the HAp bioceramic was investigated. Field emission scanning electron microscopy was used to examine the morphology of the bioceramic composites and fracture surfaces to reveal the dominant toughening mechanisms. The results showed that the sintering behaviors, toughness, and hardness of the resulting composites were significantly enhanced by the inclusion of NiO nanofibers. The fracture toughness of the Heat sintered HAp/ NiO electrospun nanofiber composites was 1.8 times higher, as the concentration of NiO electrospun nanofibers reached 5 wt%.
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Mechanical wet-milling and subsequent consolidation of ultra-fine Al2O3-（ZrO2＋3%Y2O3） bioceramics by using high-frequency Induction Heat sintering
Transactions of Nonferrous Metals Society of China, 2020Co-Authors: Khalil Abdelrazek KhalilAbstract:Abstract Alumina/zirconia composites were synthesized by wet-milling technique and rapid consolidation with high frequency Induction Heat sintering(HFIHS). The starting materials were a mixture of alumina micro-powder (80%, volume fraction) and 3YSZ nano-powders (20%). The mixtures were optimized for good sintering behaviors and mechanical properties. Nano-crystalline grains are obtained after 24 h milling. The nano-structured powder compacts are then processed to full density at different temperatures by HFIHS. Effects of temperature on the mechanical and microstructure properties were studied. Al 2 O 3 -3YSZ composites with higher mechanical properties and small grain size are successfully developed at relatively low temperatures through this technique.
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Mechanical Characterization of Cryomilled Al Powder Consolidated by High-Frequency Induction Heat Sintering
Advances in Materials Science and Engineering, 2013Co-Authors: Ehab A. El-danaf, Abdulhakim A. Almajid, Mahmoud S. Soliman, Khalil Abdelrazek KhalilAbstract:In the present investigation, an aluminum powder of 99.7% purity with particle size of ~45 µm was cryomilled for 7 hours. The produced powder as characterized by scanning, transmission electron microscopy, and X-ray diffraction gave a particle size of ~1 µm and grain (crystallite) size of nm. This powder, after degassing process, was consolidated using high-frequency Induction Heat sintering (HFIHS) at various temperatures for short periods of time of 1 to 3 minutes. The present sintering conditions resulted in solid compact with nanoscale grain size (
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A new-developed nanostructured Mg/HAp nanocomposite by high frequency Induction Heat sintering process
IOP Conference Series: Materials Science and Engineering, 2012Co-Authors: Khalil Abdelrazek KhalilAbstract:The objective of the present study was to investigate the effect nano-hydroxyapatite contents on the mechanical and microstructural properties of magnesium nanocomposites in order to develop a new biodegradable hard tissue substituent. Mg/HAp nanocomposite with various HAp contents (0-10 wt %) were prepared using pure magnesium and HAp nanopowder as raw materials. The starting material was super fast densified by high frequency Induction Heat sintering (HFIHS). The results indicated that, a uniform distribution of HAp particles was observed along the boundary between matrix particles. Nano-crystalline grains with a crystal size range of 37-50 nm were obtained. The relative densities and microhardness of the composites initially increased with increase the amount of HAp addition. Despite the short dwelling time when the current was applied, the relative density and microhardness of the sintered samples reached as high as 99.7 % and 70 HV respectively, in the composite containing 1 to 3 wt% HAp. Addition of 1 to 3 wt% of HAp improved compression strength of Mg by 16%. Addition of HAp decreases the crystal size of the nanocomposites. The mechanical properties, i.e. hardness and compressive strength are evidently increased with increasing HAp content up to 2 wt%. However, when the HAp content was larger than 2 wt%, the compressive strength decreased due to the agglomeration of HAp particles. The hardness, compressive and ultimate stress this composite
Aleksandr A. Fomin - One of the best experts on this subject based on the ideXlab platform.
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Functionally graded “Ti-base + (Ta, Ta2O5)-coatings” structure and its production using Induction Heat treatment
Composite Structures, 2020Co-Authors: Marina Fomina, Andrey M. Zakharevich, Vladimir Koshuro, A Shumilin, A Voyko, Aleksandr Skaptsov, Aleksey Steinhauer, Aleksandr A. FominAbstract:Abstract On the surface of the “Ti-base + Ta-coating” layered system, tantalum oxide coatings were obtained by Induction Heat treatment (IHT) within 600–1600 °C for 1–120 s. It was established that in the entire range of temperature and duration of IHT, the highest oxide with an oxygen concentration C[O] = 70.35–72.48 at.% was formed on tantalum. An oxide coating without cracks having an average grain size DG = 170–340 nm and pore size DP = 130–150 nm was formed at T = 1000–1050 °C. With an exposure time t = 30–120 s in the temperature range from 850 to 900 to 1000–1050 °C, high hardness values about 39–47 HRA (105–135 HV) for the tantalum layer and about 69–84 HRN15 (240–495 HV) for the near-surface layer were noted. These samples also had a superhard oxide coating with H0.01 = 55.27 ± 16.00 GPa and H0.1 = 39.09 ± 13.10 GPa. The results of the study of these samples showed that high microhardness of 1579 ± 537 HV0.2 combined with high Rockwell hardness and low defectiveness of the oxide coating allowed the creation of a mechanically stable “Ti-base + (Ta, Ta2O5)-coating” layered system.
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Composite metal oxide coatings on chromium-nickel stainless steel produced by Induction Heat treatment
Composite Structures, 2019Co-Authors: Aleksandr A. Fomin, Vladimir Koshuro, Marina Fomina, Igor RodionovAbstract:Abstract Metal oxide coatings were formed by Induction Heat treatment (IHT) on the surface of 12Cr18Ni10T stainless steel. The phase composition of these coatings comprised oxides of alloying elements, such as CrO2 (rutile-type phase), NiO, and slight amount of other oxides (Cr2O3, Fe2O3, Fe3O4). Nanosized morphology parameters were determined on the surface of steel samples with coatings subjected to low temperature IHT at T = 800–850 °C. The average size of nanograins was about 30–80 nm at an exposure within t = 30 s. The equivalent hardness value (Vickers scale, HV) of the near-surface layer was 445 ± 10 HV, which was slightly lower than the initial hardness value of untreated 12Cr18Ni10T steel. Hardness of the metal oxide coatings themselves H = 10.86 ± 4.47 GPa determined by the nanoindentation method was almost 4 times higher than the initial hardness of the steel surface. In vitro testing for biocompatibility of the metal oxide coatings confirmed that high morphological heterogeneity of the surface ensured excellent adhesion of cells.
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Functionally graded zirconium oxide coatings produced on zirconium using Induction Heat treatment
Composite Structures, 2019Co-Authors: Aleksandr A. FominAbstract:Abstract Zirconium oxide coatings were produced by Induction Heat treatment (IHT) of E110 zirconium. The IHT was performed at temperatures within 600–1200 °C for 30–300 s. According to the results of scanning electron microscopy (SEM), energy dispersive analysis (EDX), X-ray diffraction (XRD), and nanoindentation, zirconium oxide coatings with high hardness of 44.56 ± 7.40 GPa (at load of 10 mN), 25.76 ± 2.78 GPa (at load of 200 mN), and elastic modulus of 387 ± 55 GPa (at load of 10 mN), 372 ± 20 GPa (at load of 200 mN) were formed on zirconium by IHT at 800–850 °C for 300 s. The functionally graded oxide coatings consisted of a mixture of α-ZrO2 (baddeleyite) and γ-ZrO2 (cubic zirconia), the oxygen concentration on the surface reached a maximum of 69.52 ± 3.16 at% and the thickness of the oxygen-rich layer was about 8–10 μm.
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Superhard titania coatings produced on titanium using Induction Heat treatment
Ceramics International, 2019Co-Authors: Aleksandr A. FominAbstract:Abstract Superhard titania coatings were prepared by high-temperature oxidation of commercially pure (cp) titanium using Induction Heat treatment (IHT). IHT was performed at the temperatures in the range of 850–1300 °C for 1–300 s in air atmosphere. According to the results of energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), scanning electron microscopy (SEM), micro- and nanoindentation tests, titania coatings with submicron crystals characterized by high hardness H = 52–65 GPa, plasticity index H/E = 0.1–0.13, and brittle fracture resistance H3/E2 = 0.55–1.09 GPa were formed on cp-Ti due to IHT at T = 1200–1250 °C and exposure duration t = 3–5 s. The resulting TiO2 coatings indicate that there is a possibility for creating superhard materials using high-temperature conditions for the growth of crystals at the atmospheric pressure of air.
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Composite “1.2361 tool steel – Ti – TiO2” structure and its production by resistance welding with subsequent Induction Heat treatment
Composite Structures, 2018Co-Authors: Aleksandr A. Fomin, Vladimir Koshuro, Marina Fomina, Ivan Egorov, Andrey Shchelkunov, Igor RodionovAbstract:Abstract The composite “1.2361 tool steel – Ti – TiO 2 ” structure was prepared by resistance welding (RW) with subsequent Induction Heat treatment (IHT). RW of tool steel with titanium was performed at an electric power in the range of 3.5–4 kW with the pulse duration of 0.25–1.0 s. IHT was performed at the temperatures in the range of 950–1600 °C for 5–60 s for titanium inserts, and the temperature of the steel substrate did not exceed the melting point (about 1370 °C). At the electric power of 3.5 kW with the pulse duration not more than 0.5 s, Fe–Ti transition area of the weld joint with the moderate hardness about 4.0 ± 0.5 GPa (410 ± 50 HV 1 ) was formed. According to the results of scanning electron microscopy with energy dispersive X-ray analysis (EDX) and Vickers hardness test, titania coatings with high hardness about 2500 ± 250 HV 1 and 950 ± 50 HV 5 were formed on titanium surface after IHT at 1500 ± 50 °C for 30 ± 10 s. Preliminary results on the cuttability tests of the experimental replaceable cutting inserts were obtained, according to which the composite “1.2361 tool steel – Ti – TiO 2 ” structure enabled the fine turning of X40Cr13 steel (43 HRC or 415 HV).
I V Rodionov - One of the best experts on this subject based on the ideXlab platform.
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composite 1 2361 tool steel ti tio2 structure and its production by resistance welding with subsequent Induction Heat treatment
Composite Structures, 2018Co-Authors: Aleksandr A. Fomin, Vladimir Koshuro, Marina Fomina, Ivan Egorov, Andrey Shchelkunov, I V RodionovAbstract:Abstract The composite “1.2361 tool steel – Ti – TiO 2 ” structure was prepared by resistance welding (RW) with subsequent Induction Heat treatment (IHT). RW of tool steel with titanium was performed at an electric power in the range of 3.5–4 kW with the pulse duration of 0.25–1.0 s. IHT was performed at the temperatures in the range of 950–1600 °C for 5–60 s for titanium inserts, and the temperature of the steel substrate did not exceed the melting point (about 1370 °C). At the electric power of 3.5 kW with the pulse duration not more than 0.5 s, Fe–Ti transition area of the weld joint with the moderate hardness about 4.0 ± 0.5 GPa (410 ± 50 HV 1 ) was formed. According to the results of scanning electron microscopy with energy dispersive X-ray analysis (EDX) and Vickers hardness test, titania coatings with high hardness about 2500 ± 250 HV 1 and 950 ± 50 HV 5 were formed on titanium surface after IHT at 1500 ± 50 °C for 30 ± 10 s. Preliminary results on the cuttability tests of the experimental replaceable cutting inserts were obtained, according to which the composite “1.2361 tool steel – Ti – TiO 2 ” structure enabled the fine turning of X40Cr13 steel (43 HRC or 415 HV).
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composition structure and mechanical properties of the titanium surface after Induction Heat treatment followed by modification with hydroxyapatite nanoparticles
Ceramics International, 2016Co-Authors: Aleksandr A. Fomin, Natalia V. Petrova, Andrey M. Zakharevich, Vladimir Koshuro, Marina Fomina, I V Rodionov, Sergey V Dorozhkin, Aleksandr SkaptsovAbstract:Abstract Coatings of titania (TiO 2 ) and "titania–hydroxyapatite" were prepared by oxidation of commercially pure titanium VT1-00 using Induction Heat treatment (IHT), followed by modification with colloidal hydroxyapatite (HAp) nanoparticles. The IHT treatment was performed at temperatures within 600–1200 °C for 300 s. According to the results of scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray fluorescent analysis (EDX), nanoindentation and in vitro testing, titania coatings of high morphological heterogeneity, and high mechanical properties and biocompatibility were formed on the titanium surface after IHT. The coatings were found to consist of nano- and submicron crystals of oval, needle-like, plate and prismatic shapes. A subsequent modification with HAp nanoparticles of the coated titanium substrate leads to accelerated formation of mechanically strong oxidebioceramic composite coatings. It was established that the porous oxide coatings modified with nanoparticles of HAp that were formed at temperatures from 800 to 1000 °C and holding for at least 30 s had a high biocompatibility.
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chemical composition structure and properties of the surface of titanium vt1 00 and its alloy vt16 after Induction Heat treatment
Handbook of Nanoceramic and Nanocomposite Coatings and Materials, 2015Co-Authors: Aleksandr A. Fomin, I V RodionovAbstract:Abstract Oxide coatings were obtained on titanium by Induction-Heat treatment (IHT). IHT ensures growth of a titania coating represented by rutile. The experiment studied the influence of technological regimes on the surface morphology parameters of the obtained coatings, their mechanical properties, and in vitro biocompatibility. Oxide coating formation stages included the formation of dotted, needlelike, plate, and prismatic crystals. Titania coatings with high hardness of 4.23-9.86 GPa and elasticity modulus of 200-750 GPa were studied by nanoindentation. Scratch resistance was determined by scratch testing and equaled 1.38-8.76 GPa. Oxide coatings were modified with hydroxyapatite colloidal nanoparticles. The next stage comprised final Heat treatment to fix the composite structure of oxide-bioceramic coatings. The recommended temperature range 800-1000 °C of treatment during or more than 30 s was determined.
Vladimir Koshuro - One of the best experts on this subject based on the ideXlab platform.
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Functionally graded “Ti-base + (Ta, Ta2O5)-coatings” structure and its production using Induction Heat treatment
Composite Structures, 2020Co-Authors: Marina Fomina, Andrey M. Zakharevich, Vladimir Koshuro, A Shumilin, A Voyko, Aleksandr Skaptsov, Aleksey Steinhauer, Aleksandr A. FominAbstract:Abstract On the surface of the “Ti-base + Ta-coating” layered system, tantalum oxide coatings were obtained by Induction Heat treatment (IHT) within 600–1600 °C for 1–120 s. It was established that in the entire range of temperature and duration of IHT, the highest oxide with an oxygen concentration C[O] = 70.35–72.48 at.% was formed on tantalum. An oxide coating without cracks having an average grain size DG = 170–340 nm and pore size DP = 130–150 nm was formed at T = 1000–1050 °C. With an exposure time t = 30–120 s in the temperature range from 850 to 900 to 1000–1050 °C, high hardness values about 39–47 HRA (105–135 HV) for the tantalum layer and about 69–84 HRN15 (240–495 HV) for the near-surface layer were noted. These samples also had a superhard oxide coating with H0.01 = 55.27 ± 16.00 GPa and H0.1 = 39.09 ± 13.10 GPa. The results of the study of these samples showed that high microhardness of 1579 ± 537 HV0.2 combined with high Rockwell hardness and low defectiveness of the oxide coating allowed the creation of a mechanically stable “Ti-base + (Ta, Ta2O5)-coating” layered system.
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Composite metal oxide coatings on chromium-nickel stainless steel produced by Induction Heat treatment
Composite Structures, 2019Co-Authors: Aleksandr A. Fomin, Vladimir Koshuro, Marina Fomina, Igor RodionovAbstract:Abstract Metal oxide coatings were formed by Induction Heat treatment (IHT) on the surface of 12Cr18Ni10T stainless steel. The phase composition of these coatings comprised oxides of alloying elements, such as CrO2 (rutile-type phase), NiO, and slight amount of other oxides (Cr2O3, Fe2O3, Fe3O4). Nanosized morphology parameters were determined on the surface of steel samples with coatings subjected to low temperature IHT at T = 800–850 °C. The average size of nanograins was about 30–80 nm at an exposure within t = 30 s. The equivalent hardness value (Vickers scale, HV) of the near-surface layer was 445 ± 10 HV, which was slightly lower than the initial hardness value of untreated 12Cr18Ni10T steel. Hardness of the metal oxide coatings themselves H = 10.86 ± 4.47 GPa determined by the nanoindentation method was almost 4 times higher than the initial hardness of the steel surface. In vitro testing for biocompatibility of the metal oxide coatings confirmed that high morphological heterogeneity of the surface ensured excellent adhesion of cells.
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Composite “1.2361 tool steel – Ti – TiO2” structure and its production by resistance welding with subsequent Induction Heat treatment
Composite Structures, 2018Co-Authors: Aleksandr A. Fomin, Vladimir Koshuro, Marina Fomina, Ivan Egorov, Andrey Shchelkunov, Igor RodionovAbstract:Abstract The composite “1.2361 tool steel – Ti – TiO 2 ” structure was prepared by resistance welding (RW) with subsequent Induction Heat treatment (IHT). RW of tool steel with titanium was performed at an electric power in the range of 3.5–4 kW with the pulse duration of 0.25–1.0 s. IHT was performed at the temperatures in the range of 950–1600 °C for 5–60 s for titanium inserts, and the temperature of the steel substrate did not exceed the melting point (about 1370 °C). At the electric power of 3.5 kW with the pulse duration not more than 0.5 s, Fe–Ti transition area of the weld joint with the moderate hardness about 4.0 ± 0.5 GPa (410 ± 50 HV 1 ) was formed. According to the results of scanning electron microscopy with energy dispersive X-ray analysis (EDX) and Vickers hardness test, titania coatings with high hardness about 2500 ± 250 HV 1 and 950 ± 50 HV 5 were formed on titanium surface after IHT at 1500 ± 50 °C for 30 ± 10 s. Preliminary results on the cuttability tests of the experimental replaceable cutting inserts were obtained, according to which the composite “1.2361 tool steel – Ti – TiO 2 ” structure enabled the fine turning of X40Cr13 steel (43 HRC or 415 HV).
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composite 1 2361 tool steel ti tio2 structure and its production by resistance welding with subsequent Induction Heat treatment
Composite Structures, 2018Co-Authors: Aleksandr A. Fomin, Vladimir Koshuro, Marina Fomina, Ivan Egorov, Andrey Shchelkunov, I V RodionovAbstract:Abstract The composite “1.2361 tool steel – Ti – TiO 2 ” structure was prepared by resistance welding (RW) with subsequent Induction Heat treatment (IHT). RW of tool steel with titanium was performed at an electric power in the range of 3.5–4 kW with the pulse duration of 0.25–1.0 s. IHT was performed at the temperatures in the range of 950–1600 °C for 5–60 s for titanium inserts, and the temperature of the steel substrate did not exceed the melting point (about 1370 °C). At the electric power of 3.5 kW with the pulse duration not more than 0.5 s, Fe–Ti transition area of the weld joint with the moderate hardness about 4.0 ± 0.5 GPa (410 ± 50 HV 1 ) was formed. According to the results of scanning electron microscopy with energy dispersive X-ray analysis (EDX) and Vickers hardness test, titania coatings with high hardness about 2500 ± 250 HV 1 and 950 ± 50 HV 5 were formed on titanium surface after IHT at 1500 ± 50 °C for 30 ± 10 s. Preliminary results on the cuttability tests of the experimental replaceable cutting inserts were obtained, according to which the composite “1.2361 tool steel – Ti – TiO 2 ” structure enabled the fine turning of X40Cr13 steel (43 HRC or 415 HV).
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Metal oxide (Ti,Ta)-(TiO2,TaO) coatings produced on titanium using electrospark alloying and modified by Induction Heat treatment
Composite Structures, 2018Co-Authors: Vladimir Koshuro, Aleksandr A. Fomin, Marina Fomina, Igor RodionovAbstract:Abstract Metal oxide coatings (Ti,Ta)-(TiO2,TaO) on VT1-00 cp-titanium and VT16 titanium alloy (Ti-3Al-4.5 V-5.0Mo) were formed by electrospark alloying (ESA) at an operating current from 1 to 2.5 A and subsequent Induction Heat treatment (IHT) with the duration from 30 to 300 s at the temperature of 800 °C. ESA at a high operating current I = 2.5 A and subsequent IHT with a long exposure time t = 300 s ensured the formation of coatings with a high content of tantalum (about 4.5–5%) and tantalum oxide TaO (about 7–8%). The resulting coatings were characterized by high hardness of 9.5–15 GPa and elastic modulus E of 450–700 GPa.
Marina Fomina - One of the best experts on this subject based on the ideXlab platform.
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Functionally graded “Ti-base + (Ta, Ta2O5)-coatings” structure and its production using Induction Heat treatment
Composite Structures, 2020Co-Authors: Marina Fomina, Andrey M. Zakharevich, Vladimir Koshuro, A Shumilin, A Voyko, Aleksandr Skaptsov, Aleksey Steinhauer, Aleksandr A. FominAbstract:Abstract On the surface of the “Ti-base + Ta-coating” layered system, tantalum oxide coatings were obtained by Induction Heat treatment (IHT) within 600–1600 °C for 1–120 s. It was established that in the entire range of temperature and duration of IHT, the highest oxide with an oxygen concentration C[O] = 70.35–72.48 at.% was formed on tantalum. An oxide coating without cracks having an average grain size DG = 170–340 nm and pore size DP = 130–150 nm was formed at T = 1000–1050 °C. With an exposure time t = 30–120 s in the temperature range from 850 to 900 to 1000–1050 °C, high hardness values about 39–47 HRA (105–135 HV) for the tantalum layer and about 69–84 HRN15 (240–495 HV) for the near-surface layer were noted. These samples also had a superhard oxide coating with H0.01 = 55.27 ± 16.00 GPa and H0.1 = 39.09 ± 13.10 GPa. The results of the study of these samples showed that high microhardness of 1579 ± 537 HV0.2 combined with high Rockwell hardness and low defectiveness of the oxide coating allowed the creation of a mechanically stable “Ti-base + (Ta, Ta2O5)-coating” layered system.
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Composite metal oxide coatings on chromium-nickel stainless steel produced by Induction Heat treatment
Composite Structures, 2019Co-Authors: Aleksandr A. Fomin, Vladimir Koshuro, Marina Fomina, Igor RodionovAbstract:Abstract Metal oxide coatings were formed by Induction Heat treatment (IHT) on the surface of 12Cr18Ni10T stainless steel. The phase composition of these coatings comprised oxides of alloying elements, such as CrO2 (rutile-type phase), NiO, and slight amount of other oxides (Cr2O3, Fe2O3, Fe3O4). Nanosized morphology parameters were determined on the surface of steel samples with coatings subjected to low temperature IHT at T = 800–850 °C. The average size of nanograins was about 30–80 nm at an exposure within t = 30 s. The equivalent hardness value (Vickers scale, HV) of the near-surface layer was 445 ± 10 HV, which was slightly lower than the initial hardness value of untreated 12Cr18Ni10T steel. Hardness of the metal oxide coatings themselves H = 10.86 ± 4.47 GPa determined by the nanoindentation method was almost 4 times higher than the initial hardness of the steel surface. In vitro testing for biocompatibility of the metal oxide coatings confirmed that high morphological heterogeneity of the surface ensured excellent adhesion of cells.
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Composite “1.2361 tool steel – Ti – TiO2” structure and its production by resistance welding with subsequent Induction Heat treatment
Composite Structures, 2018Co-Authors: Aleksandr A. Fomin, Vladimir Koshuro, Marina Fomina, Ivan Egorov, Andrey Shchelkunov, Igor RodionovAbstract:Abstract The composite “1.2361 tool steel – Ti – TiO 2 ” structure was prepared by resistance welding (RW) with subsequent Induction Heat treatment (IHT). RW of tool steel with titanium was performed at an electric power in the range of 3.5–4 kW with the pulse duration of 0.25–1.0 s. IHT was performed at the temperatures in the range of 950–1600 °C for 5–60 s for titanium inserts, and the temperature of the steel substrate did not exceed the melting point (about 1370 °C). At the electric power of 3.5 kW with the pulse duration not more than 0.5 s, Fe–Ti transition area of the weld joint with the moderate hardness about 4.0 ± 0.5 GPa (410 ± 50 HV 1 ) was formed. According to the results of scanning electron microscopy with energy dispersive X-ray analysis (EDX) and Vickers hardness test, titania coatings with high hardness about 2500 ± 250 HV 1 and 950 ± 50 HV 5 were formed on titanium surface after IHT at 1500 ± 50 °C for 30 ± 10 s. Preliminary results on the cuttability tests of the experimental replaceable cutting inserts were obtained, according to which the composite “1.2361 tool steel – Ti – TiO 2 ” structure enabled the fine turning of X40Cr13 steel (43 HRC or 415 HV).
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composite 1 2361 tool steel ti tio2 structure and its production by resistance welding with subsequent Induction Heat treatment
Composite Structures, 2018Co-Authors: Aleksandr A. Fomin, Vladimir Koshuro, Marina Fomina, Ivan Egorov, Andrey Shchelkunov, I V RodionovAbstract:Abstract The composite “1.2361 tool steel – Ti – TiO 2 ” structure was prepared by resistance welding (RW) with subsequent Induction Heat treatment (IHT). RW of tool steel with titanium was performed at an electric power in the range of 3.5–4 kW with the pulse duration of 0.25–1.0 s. IHT was performed at the temperatures in the range of 950–1600 °C for 5–60 s for titanium inserts, and the temperature of the steel substrate did not exceed the melting point (about 1370 °C). At the electric power of 3.5 kW with the pulse duration not more than 0.5 s, Fe–Ti transition area of the weld joint with the moderate hardness about 4.0 ± 0.5 GPa (410 ± 50 HV 1 ) was formed. According to the results of scanning electron microscopy with energy dispersive X-ray analysis (EDX) and Vickers hardness test, titania coatings with high hardness about 2500 ± 250 HV 1 and 950 ± 50 HV 5 were formed on titanium surface after IHT at 1500 ± 50 °C for 30 ± 10 s. Preliminary results on the cuttability tests of the experimental replaceable cutting inserts were obtained, according to which the composite “1.2361 tool steel – Ti – TiO 2 ” structure enabled the fine turning of X40Cr13 steel (43 HRC or 415 HV).
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Metal oxide (Ti,Ta)-(TiO2,TaO) coatings produced on titanium using electrospark alloying and modified by Induction Heat treatment
Composite Structures, 2018Co-Authors: Vladimir Koshuro, Aleksandr A. Fomin, Marina Fomina, Igor RodionovAbstract:Abstract Metal oxide coatings (Ti,Ta)-(TiO2,TaO) on VT1-00 cp-titanium and VT16 titanium alloy (Ti-3Al-4.5 V-5.0Mo) were formed by electrospark alloying (ESA) at an operating current from 1 to 2.5 A and subsequent Induction Heat treatment (IHT) with the duration from 30 to 300 s at the temperature of 800 °C. ESA at a high operating current I = 2.5 A and subsequent IHT with a long exposure time t = 300 s ensured the formation of coatings with a high content of tantalum (about 4.5–5%) and tantalum oxide TaO (about 7–8%). The resulting coatings were characterized by high hardness of 9.5–15 GPa and elastic modulus E of 450–700 GPa.