Titanium Steel Research Articles

Effect of material and dimensions on the mechanical behavior of a dental implant

Abstract Metallic dental implants such as titanium and stainless steel have an elastic modulus 5-14 times greater than that of compact bone (15 GPa). These stiff implants do not adequately strain the bone, which can result in bone resorption through a phenomenon referred to as stress shielding. The implant length and diameter has a significant influence on the stress distribution within the surrounding jawbone. Therefore, the objective of this investigation is to optimize the material and the dimensions of a dental implant. A numerical solution of a 3D finite element analysis using ANSYS software was conducted to achieve this purpose. It was concluded that by using stainless steel, titanium or gold dental implants with a large diameter and short length the values of the maximum von Mises stress values in cortical bone were increased. The maximum increase in von Mises stress can be obtained by using a stainless steel implant. This dental implant will reduce the stress shielding effect as well as yield suitable values with respect to von Mises stress for both porcelain crowns and dental implants, thus increasing the service life of the implant.

Friction and wear characteristics modification via laser surface textured grooves

ABSTRACT The commensurate contact condition plays a key role in the directional friction properties and wear performance when two surfaces slide against each other. An experimental study on bidirectional friction and wear control by nanosecond pulsed laser selective texturing of grooves on AISI 304 stainless steel (SS) and TA2 titanium (Ti) surfaces of the sliding components was proposed. The influence of the aspect ratio (AR) and groove orientation angle on directional friction properties and wear performance was investigated. The AR2 and 75° samples performed best with 68.13 and 21.71% overall average coefficient of friction reduction for the Ti–Ti and SS–SS interfaces, respectively. The AR5.5 generated the least wear for the Ti–Ti and SS–SS pairs. The results take us a step closer to deriving a more effective, accurate, and dependable guideline for designing laser-machined surface grooves for directional sliding friction control.

Effect of Excess Phase Precipitation on Strengthening of Structural Steels Prepared by Hot Stamping

The contribution of nano-sized precipitates to hardening metal products prepared by hot stamping from microalloyed niobium and titanium steels is evaluated. In order to calculate the characteristics of carbide precipitates (quantity, size), kinetics are modeled for their precipitation from austenite. It is shown that the increase in yield strength due to microalloying steel with niobium is greater than with titanium, and it increases with increase in their content. With a concentration of 0.1% each of Nb and Ti, the contribution to hardening steel with 0.3% C reaches 186 and 129 MPa, respectively.

Development of hot surfaces generated by friction contacts of titanium alloy and steel

When light alloys used in coal mine, the sparks generated by mechanical friction and impacts are the main effective ignition source. While the hot surfaces are concomitant in friction process, prior to the occurrence of mechanical sparks, whether the hot surfaces will be an effective ignition source. Then this paper focuses on the development of hot surfaces generated by TC4 titanium alloy at the low friction velocities. Experiments and finite element simulation methods were used together to describe the temperature field of TC4 titanium alloy. It was found that the temperature of hot surfaces increased with the load and increased much faster at higher relative speed. By means of regression analysis, the variation law of friction coefficient and contact pressure with loads and the variation law of hot surface temperature with friction coefficient and pressure were studied, then the fitting curve of hot surface temperature was obtained. The results of calculations and experiments indicate that hot surfaces generated by light alloy was possible to be an effective ignition source for methane air mixture in coal mine.

The design of copper‐coating overpack for the high‐level radioactive waste disposal concept in Japan

AbstractFor the geological disposal system in Japan, a vitrified waste will be contained in a metal overpack, which, in turn, will be surrounded by a thick bentonite buffer. The overpack is aiming to prevent the contact of groundwater to vitrified waste during the high radioactivity and heat generation period of the first 1,000 years at least after emplacement. Within the Japanese program, consideration for overpack candidate materials has included carbon steel, copper–steel composite, and titanium–steel composite. Within the extensive safety assessment conducted in 2000, steel was selected. This selection was partly based on the manufacturability of carbon steel, as well as its well‐understood corrosion behavior. However, the understanding of copper corrosion and welding/manufacturing technologies have greatly progressed over the past two decades. In this study, we focus on the copper‐coated container developed by the Nuclear Waste Management Organization, because this technology is seemingly effective to maintain very long‐term containment of hundreds of thousands of years, with a low cost of manufacturing within the Canadian program. We are investigating the applicability of the copper‐coating technologies in terms of the corrosion allowance and mechanical design.

Effects of BaO on the Viscosity and Structure of a New Fluorine-Free CaO-Al2O3-TiO2-Based Mold Flux for High Titanium Steel

Herein, the effects of BaO (i.e. 5, 10, 15 and 20 pct) on the viscosity and structures of a new fluorine-free CaO-Al2O3-TiO2-based mold flux with w(CaO pct)/w(Al2O3 pct) ratio of 1.0 are investigated using a rotary viscometer, molecular dynamics (MD) simulations, and Raman spectroscopy. The viscosity of the samples (the testing temperature is 1300 °C) decrease from 0.46 to 0.21 Pa·s as the BaO content increased from 5 to 20 pct, and the activation energy decreases from 150.7 to 119.7 kJ·mol−1, the break temperature (Tbr) decreases from 1475 K to 1429 K which are achieved as the initial testing temperature of 1300 °C decreased under the furnace cooling. With the addition of BaO, the MD simulation results suggest that the coordination numbers (CNs) of Al (Ti)-O are reduced, while Q3, Q4, and Q5 are depolymerized into Q0, Q1, and Q2. The Raman spectroscopy results illustrate that the bridge oxygens (BOs) originating from the Ti-O-Ti (Al) linkages and Q2 (Al-O−) are depolymerized into Q1 (Si-O−) and Q0 (Al-O−) as the BaO content is increased. The Raman spectroscopy results agree well with those of the MD simulation. Therefore, BaO can simplify the structure of melts and decrease the viscosity of such systems. This work not only presents a new fluorine-free CaO-Al2O3-TiO2-based mold flux, but also deepens the understandings of the role of BaO in this system.

The influence of specific lubricants on the friction and wear properties of titanium aluminum nitride + solid carbon two-layer coating investigation

The influence of three model lubricants (inactive, surface-active and chemically active) on the friction-wear characteristics of steel—steel friction pairs, steel—coating of titanium aluminum nitride and steel—two-layer coating of titanium aluminum nitride + hard carbon coating is studied. The minimum coeffi cient of friction and the minimum diameters of the wear spot were established for the combination of steel-two-layer coating of titanium aluminum nitride + hard carbon coat ing-orientant in compared media.

Stress propagation and debonding effects in impedance-graded multi-metallic systems under impact loading

This article investigates the performance of an impedance-graded multi-metallic system. Material combinations of steel–titanium, steel–aluminium and steel–titanium–aluminium are compared against a monolithic steel configuration. The experiments were carried out using a single-stage gas gun, where the target specimens consisted of these material configurations. The targets were subjected to the impact of an aluminium flyer at a velocity of 180 m/s, where elastic waves were expected to propagate through the target. The free surface velocity of the final material in the target was measured and these readings were used to quantify the stresses in the materials. These stress results were compared with the output from two-dimensional axisymmetric numerical models and theoretical equations. The findings of this study indicated that a target configuration with gradual impedance reduction could minimize the magnitudes of both compressive and tensile stresses in the materials, where the latter is critical towards preventing debonding in a multi-material system.

Efficiency of Vanadium Barrier Layer in a Stainless Steel–Titanium Bimetal at a High Temperature

The efficiency of using a vanadium barrier layer and a bimetallic composition composed of 08Kh18N10T stainless steel + VT1-0 titanium obtained by means of explosion welding in order to prevent occurrence of an intermetallic layer is studied in different temperature ranges. The evolution of the heat-affected zone in the samples subjected to heating to 600, 700, 800, and 900°C with exposure times of 1, 3, 5, and 10 h is studied with the use of scanning electron microscopy and metallography, and also the microhardness is measured. It is shown that the vanadium barrier layer reliably prevents mutual diffusion between steel and titanium at a high temperature, which excludes the formation of intermetallic compounds in the heat-affected zone. The efficiency of the barrier layer is evaluated.

Criterial Parameters for Achieving the BH Effect in Ultralow-Carbon Steels for Deep Drawing

Key technological parameters of the stable production of interstitial free (IF) grade steel sheet with the bake hardening (BH) effect have been studied. The features of ultralow-carbon IF grade steels and IF steels with the BH effect, as well as the process flowchart for hardening IF-BH steel during hot drying of a car body after painting are described. Data concerning the chemical composition of IF and IF-BH steels produced at Russian and foreign enterprises are presented. The causes of slip band defects in steel sheet occurring when the yield plateau is observed in the tensile diagram of steel samples are analyzed. Requirements for the shelf life of IF-BH steel grades are presented and analyzed. A calculation formula of effective carbon content in steel is proposed based on the content of total carbon, niobium, titanium and nitrogen in steel. The range of effective carbon content in steel required for achieving the optimal BH effect magnitude is presented based on the papers published earlier. The industrial IF-BH steel production results have been analyzed for Russian enterprise conditions. In addition, the following criteria are recommended: the optimum range of carbon content in solid solution, the recommended maximum total concentrations of carbon and nitrogen in steel, and the BH effect magnitude that provides a high yield of IF-BH steel sheet fit for production. The calculations of various IF-BH steel microalloying with titanium and niobium have been performed. Criteria have been formulated that for obtaining a given BH effect magnitude in cold-rolled ultralow-carbon steels. A two-stage scheme for microalloying with titanium and niobium is proposed. The grain size influence in sheet steel upon the presence and BH effect magnitude, as well as upon the presence or absence of a yield plateau observed in the sheet metal’s tensile diagram in the initial state, is described.

Ion-beam processing of metallized carbon fiber-reinforced plastics

ABSTRACTThe paper studies the effect of ion treatment of carbon tapes and their subsequent metallization on the increase in interlaminar shear strength of carbon plastics. The time of the ion treatment varied. Two types of carbon tapes (LU-0.1P and FibARM Tape-230 | 300) were used as the fiber base of the composite material. Titanium and stainless steel were used as the coating metal. The ion source II200 was used, when conducting ion treatment. Methods of magnetron and vacuum-arc coating were applied using the equipment Bulat-6 and Mir-2. Recommendations are formulated for rational combinations of materials used and technological regimes that provide an increase in interlaminar shear strength of the composite material.

Properties of Novel High Temperature Titanium Alloys for Aerospace Applications

The attractive combination of strength and low density has resulted in titanium alloys covering 15 to 25% of the weight of a modern jet engine, with titanium currently being used in fan, compressor and nozzle components. Typically, titanium alloys used in jet engine applications are selected from the group of near alpha and alpha-beta titanium alloys, which exhibit superior elevated temperature strength, creep resistance and fatigue life compared to typical titanium alloys such as Ti-6Al-4V. Legacy titanium alloys for elevated temperature jet engine applications include Ti-5Al-2Sn-2Zr-4Mo-4Cr, Ti-6Al-2Sn-4Zr-2Mo-0.1Si and Ti-4Al-4Mo-2Sn-0.5Si. Improving the mechanical behavior of these alloys enables improved component performance, which is crucial to advancing jet engine performance. As a world leader in supplying advanced alloys of titanium, nickel, cobalt, and specialty stainless steels, ATI is developing new titanium alloys with improved elevated temperature properties. These improved properties derive from precipitation of secondary intermetallics in alpha-beta titanium alloys. ATI has developed several new alpha-beta titanium alloy compositions which exhibit significantly improved elevated temperature strength and creep resistance. This paper will focus on the effects of chemistry and heat treat conditions on the microstructure and resulting elevated temperature properties of these new aerospace titanium alloys.

Microstructure-Property Relationships in Cold Rollable, High-Strength α/β Alloys

For decades Ti-6Al-4V has been the workhorse alloy for aerospace sheet applications due to its good balance of properties and the known ability to hot roll it with relative ease. Sheet of Ti-6Al-4V is made by hot pack rolling, which is a costly and time consuming process, due to the alloy having insufficient room-temperature workability to support significant cold reduction or forming. Consequentially, Ti-6Al-4V is not typically offered in foil gauges, since the direct product of hot pack rolling contains an undesirable surface finish and insufficient gauge control. Hot pack rolling also limits the maximum sheet size and annual capacity. As a world leader in advanced sheet alloys of titanium, nickel, cobalt, and specialty stainless steels, ATI is developing new titanium alloys with improved strength compared to Ti-6Al-4V that take advantage of a recent understanding of cold workability in high-strength alpha-beta titanium. These α+β alloys exceed Ti-6Al-4V strength while being highly cold formable. Cold rolling via coil processing also enables longer lengths of sheet with significantly improved gauge control and surface finish. Results from pilot scale ingots will be presented upon, including final properties of these unique alloys and microstructure-property correlations developed through modelling.

Structure and Phase Composition of Ti–6Al–4V Alloy Obtained by Electron-Beam Additive Manufacturing

The paper presents the fabrication of Ti–6Al–4V alloy specimens using two operating modes of the electron beam additive manufacturing (EBAM). The structure, phase composition and microhardness of the obtained alloy specimens are investigated. The EBAM process includes a deposition of Ti–6Al–4V wire onto a substrate comprising of VT1-0 (grade 2) titanium alloy and 12Kh18N10 (AISI 321) stainless steel. It is shown that at a high electron beam current, the height and width of the β-phase columnar grains are lower than at a low electron beam current. This phenomenon is discussed in terms of stabilization of the temperature gradient and the increased cooling rate during the building process. This phenomenon is caused by the formation of Fe2Ti, FeTi and Cr2Ti intermetallic phases in the diffusion bonding appeared between the titanium and stainless steel plates.

Research of corrosion stability of steel brand 12X18H10T and titanium brand ВT1–0 for solder baths

General global trend of reduce the proportion of physical experiment when designing equipment led to an increase in the significance of the calculation and to tighten the requirements for its conduct. The study was carried out corrosion resistance of steel brand 12X18H10T and titanium brand ВT1–0 for solder baths. Based on the experiments of corrosivity was concluded that preparing the metal surface of the solder baths is a determining factor. Corrosion of the samples was uneven over the entire surface, the main corrosivity is manifested during the first 50 hours. Further etching of the samples leads to a slow decrease in the corrosion rate with the exit to the plateau. Thanks to this study, it has been established that steel brand 12X18H10T and titanium brand ВT1–0 are acceptable structural materials and are proposed for use in mass production.

Raspredelenie azota, titana i alyuminiya mezhdu nitridami i tverdym rastvorom v stalyah tipa ATYu

Quantitative data on the distribution of nitrogen, titanium and aluminum between nitrides and solid solution have been established in ATU steels. The optimal amount of titanium in 20ATU steel was determined, which leads to the best interfacial distribution of nitride-forming elements (N, Al, Ti) under hot rolling conditions. For the most complete binding of nitrogen to AlN nitrides, the amount of aluminum in 20ATU steel should be ≥40 10-3 wt. %. To obtain fine nitrides and maintain a sufficiently high fluidity of steel 20ATU optimal content of aluminum should be (40-60) 10-3 wt. %. It is recommended to subject ATU type steels to heat treatment at optimal temperature and time Keywords: Carbon, low-alloy steels, nitrogen, titanium, aluminum, interfacial distribution

Neutron reflector analysis for the beam-port of the Missouri S&T Reactor

A preliminary neutron reflector material selection and feasibility study of an inexpensive reflector replacement for the neutron beam-port at the 200 kW Missouri University of Science and Technology Research Reactor (MSTR) was conducted using Monte-Carlo techniques. The Monte-Carlo N-Particle transport code (MCNP6.1) was used to model the neutron beam-port of the Missouri S&T Reactor in order to study the effects of adding different reflector materials, in terms of the neutron flux reaching the radiography/tomography facility in front of MSTR’s neutron beam-port. Aluminum, beryllium, titanium, nickel, nickel-58, lead, bismuth, tungsten and stainless steel reflectors were modeled to find the best neutron reflector for the beam-port. After examining reflector materials, it was concluded that none of them were an improvement over the current design. Experimental thermal flux was measured to be 1.0 × 107 ± 3.16 × 103 cm−2 s−1 at the exit of beam port for current version of beam-port. The current ratio of beam port inlet and outlet obtained from simulations was found to be 3.37 × 104. The flux of beam port inlet was determined on the order of 1.0 × 1011 cm−2 s−1 which is consistent with previous findings.

Produção de um compósito de aço AISI tipo 1020 com titânio por cladeamento

O objetivo deste trabalho é descrever a proposta de pesquisa de uso do cladeamento para produção de uma estrutura tipo sanduiche de aço AISI tipo 1020 e titânio. O trabalho foi apresentado no VI Workshop GPESE do Grupo de Pesquisas em Sistemas de Exaustão da Universidade Federal de Itajubá. Utiliza-se uma breve revisão bibliográfica a fim de investigar na literatura os principais componentes do processo de cladeamento, para a obtenção de um compósito do tipo sanduíche. Espera-se que as propriedades da chapa de aço combinadas com o pó de titânio, gere um material que tenha um fio de corte duradouro onde é colocado o titânio, e as superfícies, tanto inferior quanto superior, tenha boa resistência ao impacto.

Production of ship steel—titanium bimetallic composites through explosive cladding

Titanium was combined with ship steel sheet through the explosive cladding technique using different explosive ratios. The effects of the explosive ratio on the microstructure, mechanical and corrosion properties of the ship steel-titanium bimetallic composites were investigated. The microstructural characterization of the bimetallic composites was studied by optical microscopy (OM), scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS). The mechanical properties were determined through tensile-shear, impact toughness, bending, twisting and microhardness testing, while the corrosion behaviour was examined using neutral salt spray (NSS) tests. The microstructure studies revealed that a wavy joining interface was attained at higher explosive ratios, while a completely smooth interface was achieved at the lowest explosive ratio. In the microhardness tests, the highest hardness values were attained from both sides of the joining interface. Conclusions of the mechanical tests separation did not occur in the interfaces of the bimetallic composite specimens. In the corrosion test, the titanium was found to have higher corrosion resistance than the ship steel sheet. It was concluded that the mechanical and corrosion properties of the ship steel sheet can be enhanced by explosive cladding with titanium.

Improvement of the Neutron Production Rate of IEC Fusion Device by the Fusion Reaction on the Inner Surface of the IEC Chamber

Neutrons are generated in the inertial electrostatic confinement (IEC) device through different types of fusion reactions of the fuel gas such as deuterium (D) and tritium (T). Fusion in the IEC device takes place via various kinds of collisions like beam-beam collision, beam–background gas collision, and beam-target collision on the electrode surfaces. Two identical anodes for the IEC chamber made from titanium (Ti) and SUS-316L stainless steel (SS) are used to study the effect of the anode material on the neutron production rate (NPR). The NPRs from the chambers are measured at different applied powers. The achieved NPRs, so far, for Ti and SS are 8.9 × 107 n/s at 5.25 kW (75 kV, 70 mA) and 2.8 × 107 n/s at 10.5 kW (70 kV, 150 mA), respectively. The normalized NPR (NPR rated to the cathode current) from the Ti chamber is three to four times higher than that from the SS chamber. We observed a better NPR for the Ti chamber compared with the SS chamber. This is explained by the fusion reaction occurring between the neutrals and D atoms adsorbed/embedded on the inner surface of the anode. Moreover, the Ti chamber shows an improvement of the NPR as a function of the operating time ranging from 1.5 to 1.75 after 25 h from the first discharge.