Effect Of Additional Elements Research Articles

Evaluation of Forged TiAl Alloy Usefulness Based on Their Impact Resistance

The purpose of this study is to determine if forged TiAl alloys are worth using for small parts such as jet engine turbine blades. As part of this goal, this study investigated ways to improve the impact resistance of forged TiAl alloys and compared them to cast TiAl alloys. The effects of additive elements and microstructure on the impact resistance of forged ternary TiAl alloys of 43.5 at. % Al were evaluated using the Charpy impact test on specimens heated to 500 °C prior to testing. The impact resistance of the forged alloys improved with the addition of Cr, V, and Mn and deteriorated with the addition of Nb. The impact resistance of the microstructure containing a β-phase, a common microstructure in forged TiAl alloys, was significantly lower. The fully lamellar structure obtained at the expense of forgeability showed much higher impact resistance than this. However, even the best impact resistance of the forged alloys was significantly inferior to that of cast ternary alloys of 46.5 at. % Al prepared with the same additive content. Combined with the high cost and low high-temperature strength of the forged TiAl alloys, it is concluded that it is pointless to use forged TiAl alloys for small parts that can be made via casting.

Effect of Additional Element on Local Mechanical Properties of High Purity Aluminum Alloys by Nanoindentation

Effect of Additional Element on Local Mechanical Properties of High Purity Aluminum Alloys by Nanoindentation

Effect of Additive Element on Fatigue Properties of Sn-Sb-Ag High Temperature Lead-Free Solder

Effect of Additive Element on Fatigue Properties of Sn-Sb-Ag High Temperature Lead-Free Solder

A comparative study of the bio-tribocorrosion behaviour of PEO coated AZ31 magnesium alloy in SBF: Assessing the effect of B, Cu and Zn doping

AZ31 alloy is a widely used material in biomedical applications. It is an alternative alloy for temporary implantation due to its low weight and superior biocompatibility. However, surface properties such as wear and corrosion are quite weak compared to other metallic biomaterials. It is extremely important to improve the surface properties, as these two mechanisms cause very serious material damage on Mg alloys separately or synergistically. In this context, oxidation processes are carried out with the plasma electrolytic oxidation (PEO) method, which provides very successful adhesion in alloys such as AZ31. In this study, the tribocorrosion performance of the films produced by doping Cu, B and Zn elements using PEO was investigated. The simultaneous effects of corrosion and wear mechanisms on surfaces were investigated with experiments carried out in artificial body fluid (SBF). It was concluded that the porous oxide films undergo morphological changes with the effect of additive elements, this change in morphology has a barrier effect, especially against corrosion attacks, and the improved corrosion resistance also improves the wear performance. According to the OCP measurements made under wear, the surface that showed the most noble behavior was Zn-doped (−0.71 V). A similar behavior can be mentioned for the wear test carried out together with the potentiodynamic polarization test. It minimized the Zn current density value in the structure (2.3 × 10−6 A/cm2).

Engineering formulation of the irradiation growth behavior of zirconium-based alloys for light water reactors

Improved Zr-based cladding alloys of which the composition was changed from conventional Zircaloy have been developed by nuclear fuel vendors and utilities. Since the irradiation growth of fuel cladding is one of the most important parameters which determine the dimensional stability of fuel rods and/or fuel assemblies during normal operation, irradiation growth data of such alloys are necessary for safety analysis and proper design of fuel rods and/or fuel assemblies. The irradiation growth behavior of coupon specimens prepared from improved Zr-based alloys for light-water reactor fuel cladding, which have various additive elements and fabrication process, was investigated by conducting an irradiation test at 573 and 593 K under typical PWR coolant conditions up to a fast-neutron fluence of ≈7.8 × 1021 (n/cm2, E >1 MeV) in the Halden reactor in Norway. Based on the dimensional change data measured at interim and final inspections, the amounts of irradiation growth of the improved Zr-based alloys were formulated from the viewpoint of engineering. The trends of the parameters which express the effects of additive elements on irradiation growth behavior were in good agreement with those previously reported, and it was found that the amount of irradiation growth can be expressed by using a summation rule of the effect of each additive element on irradiation growth.

Selection of Additive Elements Focusing on Impact Resistance in Practical TiAl Cast Alloys

Despite the widespread use of TiAl alloys in many fields, their poor impact resistance has recently emerged again as a major issue. Therefore, in this study, the practical effects of additive elements were examined by considering impact resistance as the most important property of practical TiAl cast alloys. The impact resistance was evaluated via the Charpy impact test, which has been rarely applied to TiAl alloys, revealing that only V, Cr, Mn, and B slightly improved the impact resistance, compared to that of the Ti–Al binary alloy, both in the as-cast and heat-treated states. In contrast, Nb, Mo, W, Fe, Ni, Si, C, and N decreased the impact resistance. If a slight decrease in impact resistance is permitted, then only Si and C can improve the creep strength, and Nb and W can improve the anti-oxidation resistance. These results confirm the excellence of practical TiAl cast alloys developed a considerable time ago, containing these elements in addition to Cr, Mn, and B.

Effect of Additive Elements (x = Cr, Mn, Zn, Sn) on the Phase Evolution and Thermodynamic Complexity of AlCuSiFe-x High Entropy Alloys Fabricated via Powder Metallurgy

In this study, equimolar AlCuSiFe-x (x = Cr, Mn, Zn, Sn) HEAs were fabricated by mechanical alloying (MA) and spark plasma sintering methods (SPS). The MA was performed for 45 h followed by densification of powder compacts at 650 °C. The results revealed the formation of dual face-centered cubic (FCC) and body-centered cubic (BCC) structures in AlCuSiFe-x (x = Zn, Sn) while a single BCC solid solution was noticed in AlCuSiFe-x (x = Cr, Mn). After SPS treatment, AlCuSiFeSn alloy contained FCC with CuxSny while AlCuSiFe–Zn changed to FCC + BCC structure. Similarly, AlCuSiFeCr and AlCuSiFeMn showed the formation of BCC + FCC with additional σ- and µ-phases in the HEA matrix. The calculated thermodynamic parameters of HEAs also supported the formation of different solid-solution phases in each of the above HEAs. It was found that HEAs with the additive elements Sn and Zn tend to have major FCC phases, while those with Cr and Mn give rise to major BCC with brittle σ- and µ-phase, which further improves their mechanical strength. Graphic Abstract

Effect of Additive Elements in Copper Alloys for Ants’ nest Corrosion on Brazing–Ability

Effect of Additive Elements in Copper Alloys for Ants’ nest Corrosion on Brazing–Ability

The effect of additional element dissolving on the solid solubility of Zn in Mg alloy: A first-principles prediction strategy

The solid solubility of Zn is an important factor for designing the Mg-Zn based alloy. This work aims at developing a strategy to predict the effect of additional element dissolving on the solid solubility of Zn in Mg alloy based on the first-principles calculation. The strategy is composed of two criteria. The behaviors of X in controlling the lattice distortion and energy fluctuation caused by Zn-Mg interaction are investigated as the main criterion, and the precipitation of Zn accelerated by Zn-X interaction is further examined as the supplementary criterion. After considering the metallic elements across the periodic table (period II to VI), Ca is recommended as the element enhancing the solid solubility of Zn and the others are recommended as the elements reducing the solid solubility, which has a considerable agreement with the available thermodynamic assessments. The first-principles strategy suggests that an element X enhancing the solid solubility of Zn in Mg alloy should satisfy two conditions. Firstly, X can provide the opposite geometric and energetic effect of single Zn on Mg host, and secondly, there is no attractive interaction between Zn and X. This work explores a pathway for extending Hume-Rothery rules from the binary alloy system to the ternary, which serves the development of alloy design theory.

Effects of alloying elements in high reliability copper wire bond material for high temperature applications

Recently, a shift from Au bonding wire to Cu bonding wire is expected for automotive application. Palladium coated copper (PCC) wire is strong candidate since it is widely used in LSI packages owing to its high performance and low cost. In order to apply PCC wire to automotive devices, long-term reliability specific to automobiles including stable operation under harsh environment with high temperature and humidity is required. However, pitting corrosion at the wedge bond portion was reported with PCC wire under high temperature storage life (HTSL) test. Depending on the surrounding environment such as mold compound, it is difficult for conventional PCC wire to achieve the target of automotive application. A newly developed PCC wire (EX1R) has thus developed. By using additive element in Cu core, halide induced interface corrosion and also pitting corrosion can be prevented successfully. In this paper, effect of additive element on the corrosion resistance will be discussed. The result shows that additive element forms protective passivation layer on the intermetallic compound (IMC) and Cu surface. Thereby, EX1R improves bond reliability even under severe reliability test condition.

Effect of Additional Element on Super Plasticity Deformation of Sn-Bi Alloys

Effect of Additional Element on Super Plasticity Deformation of Sn-Bi Alloys

Electrodeposited Mcraly Coatings for Gas Turbine Engine Applications

Electrolytic codeposition is a promising alternative process for fabricating MCrAlY coatings (where M = Ni, Co, or Ni + Co) for protecting high-temperature components used in various industrial gas turbine engines. The coating process involves codeposition of CrAlY-based particles and a metal matrix of Ni, Co, or (Ni,Co), followed by a diffusion treatment to convert the composite coating to the desired MCrAlY microstructure. Despite the advantages of low cost and non-line-of-sight, this coating process is less known compared to electron beam-physical vapor deposition and thermal spray processes for manufacturing high-temperature coatings. This presentation provides an overview of the electrodeposited MCrAlY coatings for gas turbine applications, highlighting the unique features of this coating process and some important findings in the past 30 years. Recent coating development progress from a collaborative research project between Tennessee Tech University and Oak Ridge National Laboratory will be presented. The effects of additional elements (e.g., Ta, Si and Hf) on the coating oxidation/corrosion performance will be discussed.

The effect of refractory (Zr, Hf) elements on the magnetocaloric property of Mn-based alloys

This study was investigated the effect of additional elements on the magnetocaloric property in MnFeMPGe (M = Zr, Hf) alloys. The magnetocaloric property of alloys depending on the decrease of the additional element was enhanced about 7.52J/kgK and 94.84J/kg at 242 K in the Mn1.2Fe0.79Zr0.01P0.6Ge0.4 alloy. We were able to deduce that the magnetocaloric property was affected by the strong magneto-crystalline anisotropy resulting from high volume % of main phase (≥50%). The strong magneto-crystalline anisotropy was induced by the homogeneous dendritic structures and distinct main peak with 112¯0 plane in Mn1.2Fe0.8−x(Zr,Hf)xP0.6Ge0.4 (x = 0.01, 0.05, 0.1) alloys.

Effect of additive elements on seizure resistance of copper alloys for high-speed plain bearings

Effect of additive elements on seizure resistance of copper alloys for high-speed plain bearings

Effect of Additional Elements on the Magnetostrictive, Magnetic and Mechanical Properties of Co-Rich Fe-Co Alloys

Effect of Additional Elements on the Magnetostrictive, Magnetic and Mechanical Properties of Co-Rich Fe-Co Alloys

Effect of Additive Elements Bi/Ni/Ge on Crack Initiation and Propagation for Low-Ag Solders

This study discusses an effect of additive elements on crack propagation behaviour for low-Ag contain Sn1.0Ag0.7Cu lead-free solders at high temperature. A cyclic push-pull loading tests for four kinds of Sn1.0Ag0.7Cu solders were conducted at 313 K with a single hole specimen. Stress amplitude of solders containing additive element Bi were bigger than that of Bi-free solders. Crack initiation cycle of solders containing Bi were earlier than that of Bi-free solders. Low-Ag solders containing Bi had shorter crack propagation cycles than that of Bi-free solders. These results indicate that the additive element Bi have the effects on the crack initiation and propagation cycles, that is, Bi accelerates the crack propagation rate. We also discuss the adaptation of J-integral range parameter to the crack propagation rate evaluation for solders. J-integral range parameter evaluates the crack propagation rate for low-Ag solders independent of the additive elements.

Solute interaction effects on grain boundary segregation in ternary alloys

In polycrystalline materials, the segregation of elements to grain boundaries (GBs) can be harmful, e.g., embrittling the GB, or helpful, e.g., strengthening the GB or stabilizing nanocrystalline states, depending on the alloying elements present. While the GB segregation tendency in binary alloys can be reasonably estimated, the effect of additional elements on this equilibrium remains largely speculative, making it difficult to design the GB chemistry of ternary alloys. Using a lattice-model framework and Monte Carlo simulations, we develop a first-order theoretical framework with which the GB segregation behavior in ternary alloys can be estimated based on the thermodynamic properties of the constituent binary systems. We then experimentally study GB segregation in the Pt-Au-Pd system as a case study. In line with our predictions, this system exhibits induced co-segregation of Pd to GBs at 400 °C, driven by the presence of Au.

Effect of additional elements on the low-cycle-fatigue characteristics of Sn-1.0Ag-0.7Cu solder obtained using a miniature-sized specimen

The low-cycle-fatigue properties of lead-free solders based on Sn-1.0Ag-0.7Cu were investigated using miniature-sized specimens. Their mechanical properties were improved by adding bismuth, nickel, and germanium. The effects of additional elements upon the low-cycle-fatigue characteristics of Sn-1.0Ag-0.7Cu, Sn-1.0Ag-0.7Cu-2.0Bi, Sn-1.0Ag-0.7Cu-0.07Ni-0.01Ge, and Sn-1.0Ag-0.7Cu-2.0Bi-0.07Ni-0.01Ge were studied and found to change. The number of cycles to failure of the two solders with bismuth was shorter than those of the two without bismuth. Regarding added nickel and germanium, there were as many cycles to failure of Sn-1.0Ag-0.7Cu-0.07Ni-0.01Ge as there were to Sn-1.0Ag-0.7Cu without nickel or germanium. The stress amplitudes of the two solders with bismuth were higher than those without bismuth. The number of cycles to failure of four solders can be expressed using energy parameters. Microstructures were observed to investigate the differences in the stress range response (softening) and fracture mechanism.

Effect of Additive Elements on the Elinvar and Invar Characteristics of Fe–Mn Base Alloys

Effect of Additive Elements on the Elinvar and Invar Characteristics of Fe–Mn Base Alloys

The Effect of Additive Element on the Properties of Mechanically Alloyed Fe-Y2O3 Alloys

Abstract In the present work, we have examined the effect of Ti on the properties of Fe-Y2O3 alloys. The result showed that the addition of Ti was effective for improving mechanical properties. This is due to the reduction of oxides by Ti during mechanical alloying and hot-consolidation. In particular, iron oxides are effectively reduced by the addition of Ti. Compared to the pristine Fe-Y2O3 alloys, titanium-added alloys exhibited fine and uniform microstructures, resulting in at least 60% higher tensile strength.