Effect Of Element Addition Research Articles

Effects of element addition on the microstructure and thermophysical properties of seven-principal cations rare-earth high-entropy oxide

Three new rare-earth high-entropy oxides with compositions of (Y1/7La1/7Nd1/7Sm1/7Gd1/7Yb1/7Lu1/7)2O3 (7HEO), (Y1/8La1/8Nd1/8Sm1/8Gd1/8Yb1/8Lu1/8Ce1/8)2O3 (8HEO) and (Y1/10La1/10Nd1/10Sm1/10Gd1/10Yb1/10Lu1/10Ce1/10Zr1/10Hf1/10)2O3 (10HEO) were prepared using a solid-state reaction method combined with conventional sintering at 1600 °C for 10 h 7HEO has a monoclinic structure. The addition of Ce into 7HEO not only leads to the phase transformation from monoclinic to bixbyite structure, but also contributes to the grain refinement. When the three elements of Ce, Zr and Hf are added into 7HEO, a second fluorite-structured phase forms and further promotes the grain refinement. 10HEO and 8HEO have a higher thermal conductivity compared with 7HEO in 25–600 °C. When the temperature reaches 900 °C, the thermal conductivity of 8HEO is lower than that of 7HEO. The addition of Ce or Ce/Zr/Hf into 7HEO causes the weakening of the bond strength and the increase of the bond length of cation-O2- in the samples, which in turn increases the thermal expansion coefficient. Moreover, 7HEO possesses a better oxygen barrier property compared with 8HEO and 10HEO. The hardness and Young's modulus of 7HEO are lower than those of 8HEO and 10HEO.

Effect of Element Addition, Microstructure Characteristics, Mechanical Properties, Machining and Welding Processes of the Hadfield Austenitic Manganese Steel

Effect of Element Addition, Microstructure Characteristics, Mechanical Properties, Machining and Welding Processes of the Hadfield Austenitic Manganese Steel

Elemental effect on formation of solid solution phase in CoCrFeNiX and CoCuFeNiX (X = Ti, Zn, Si,Al) high entropy alloys

ABSTRACTThe paper aims to investigate the effect of elements addition, its enthalpy of mixing, crystal structure and atomic size difference on the formation of solid solution phase during the synthesis of high entropy alloy (HEA) by mechanical alloying. For this CoCrFeNiX and CoCuFeNiX (where X = Ti, Zn, Si, Al), alloys were prepared by mechanical alloying. The phases formed during mechanical alloying were characterised by X-ray diffraction analysis, transmission electron microscopy and differential scanning calorimetry. Titanium and Aluminium addition facilitate solid solution formation during mechanical alloying. Formation of a BCC and FCC solid solution phase was observed for CoCrFeNiX and CoCuFeNiX system (where X = Ti, Al), respectively. Single solid solution phase was not observed for CoCrFeNiZn, CoCrFeNiSi, CoCuFeNiZn and CoCuFeNiSi HEA up to 20 hours of milling.

Effect of Element Addition and Heat Treatment Process on the Properties of High Manganese Steel

The changing of properties of HMnS by alloy elements addition and heat treatment was presented. Studying about the hardness of HMnS were increased when the Mn contents increased. On the other hand, the Cr content has effective on the hardness and microstructure of this steel also, but with the Cr content was increased from 2% to 2,5%, the hardness of high Manganese steel was not much changed. With the research about HMnS, it was added the Cr and applied the advanced heat treatment process, the microstructure of this steel was formed the chrome carbide particles with grain fine which dispersed in the matrix with the formation of these dispersed carbide particles will contribute to increasing the alloy's abrasion resistance. With the difference in heat treatment processes, the microstructure and hardness were also changed. When the sample was heat-treated according to the model heat treating; the particle size of the sample is also significantly reduced. This explains why the hardness value of the sample increases significantly. Also, under the impact load, on the surface layer of this steel, the microstructure does not appear the martensite structure form but only see the twinning on the surface. These are new findings on the mechanism transformation of high manganese austenite steel when working under the impact of the impact force. The mechanism of transformation is quite different from the previous view of phase transformation under the impact force of high manganese austenitic steel.

Evaluation of Non-proportional Multiaxial Fatigue Strength of Lead-free Solder with Elements Addition

The effect of element addition on creep and fatigue properties of Sn1.0Ag0.7Cu solder with addition of nickel, germanium and bismuth are reviewed. Element additions imporove creep properties although those deteriorate fatigue properties. From above results, necessity of non-proportional multiaxial fatigue tests are discussed. The load cell with high sensitivity was designed by making to detect small load during fatigue test was developed by making the strain detection part hollow circular. The inner diameter and the outer diameter of the load cell satisfying the condition that excessive strain does not occur regardless of high sensitivity was determined by strength calculation.

Effects of element addition on liquid phase separation of Bi-Ga immiscible alloy: Characterization by electrical resistivity and coordination tendency

The application of immiscible alloys is limited by their macrosegregation caused by liquid phase separation upon solidification. So liquid phase separation tendency is the primary factor should be concerned in the design of an immiscible alloy. In present work, the effects of tin and indium additions on liquid phase separation of Bi33.3Ga66.7 (at.%) immiscible alloy were studied by electrical resistivity measurement. It is observed that the liquid phase separation tendency of Bi33.3Ga66.7 alloy is weakened by tin but enhanced by indium addition within a minor quantity. Based on thermodynamic calculations, the effects of element additions on liquid phase separation of immiscible alloy were understood in the viewpoint of coordination tendency between elements: liquid phase separation tendency of immiscible alloy is weakened by the element addition which presents homo-coordination tendency with both the constituent elements of the immiscible alloy in liquid state; liquid phase separation tendency is enhanced by the element addition which presents hetero-coordination tendency with one of the constituent elements of the immiscible alloy but homo-coordination tendency with the other in liquid state.

Creep Characteristic of Sn1.0Ag0.7Cu Lead-Free Solders with Element Addition

In this study, creep properties of lead-free solders based on Sn1.0Ag0.7Cu were investigated. In the solders, germanium, nickel and bismuth were added to improve their mechanical properties. The effect of element addition on their microstructure and creep properties were studied. Creep properties were improved with the element addition. Creep rupture lifetime was the longest for SnAgCuBiNiGe, and that of SnAgCuBi was the second longest. It was made clear that a minimum creep strain rate is useful for lifetime prediction of the solders. An observation of microstructure was performed and coarsening of intermetallics after creep test was identified, resulting in creep rupture. It was found that the addition of bismuth hinders the coarsening of intermetallics and is effective to improve the creep properties of the solders.

Thermophysical property measurements and thermal energy storage capacity analysis of aluminum alloys

Ten aluminum alloy samples are prepared using a casting method by carefully designing compositions of Al-Si, Al-Cu, Al-Mg, and Al-Cu-Zn alloys. This paper measures the phase change temperature, latent heat, and specific heat of the samples using a differential scanning calorimeter (DSC), the thermal diffusivity using a laser flash method, and derives the thermal conductivity of each sample. The effects of element addition and temperature on the performance of the aluminum alloy phase change materials (PCM) are comprehensively analyzed. The thermal energy storage (TES) capacities of the samples in different temperature ranges are also analyzed. The results show that adding Cu, Zn, and Si to an aluminum alloy helps reduce the melting point of the alloy. The addition of dense elements such as Cu and Zn in aluminum alloys improves the alloy’s TES capacity per volume unit. Based on experimental results, this paper also recommends fitting formulas for calculating the temperature dependent specific heat and thermal conductivity of the aluminum alloys studied.

Effects of elemental addition on the microstructure, thermal stability, and magnetic properties of the mechanically alloyed FeSiBAlNi high entropy alloys

The effects of element addition, Co, Cu, and Ag on the microstructure, thermal property and magnetic properties of mechanical alloyed FeSiBAlNi high entropy alloys (HEAs, base alloy) have been investigated in depth in the present work. The FeSiBAlNi (Co, Cu, Ag) amorphous HEAs have been successfully fabricated by mechanical alloying process. The results reveal that Co and Cu additions obviously shorten the formation time of fully amorphous phase, therefore, leading to enhanced glass forming ability of the base alloy. The final milling product of FeSiBAlNiAg consists of amorphous phase and nanocrystals with face-centered cubic (FCC) structure. In addition, Co addition obviously improves the thermal stability of the base alloy, while Cu and Ag additions present the detrimental effects. Moreover, the as-milled HEAs exhibit the semi-hard magnetic property. However, the saturation magnetization (Ms) values become decreased with element additions. It suggests that the coexistence of FCC and body-centered cubic (BCC) phase gives rise to a higher Ms than a single amorphous phase or mixture of amorphous and FCC phases. Additionally, the phase formation mechanisms of amorphous and solid solution phases, as well as the correlation between the microstructure and magnetic properties have been discussed, which can be beneficial to the design of novel alloy systems.

Effects of element addition on the β→α transformation in tin

The influence of 1 wt.% Pb, Cu, Ge and Si on the transformation kinetics of the β-Sn→α-Sn transformation in high-purity powder mixtures was examined using synchrotron powder X-ray diffraction. Pb and Cu were found to be effective in suppressing α–tin growth. Ge and Si inhibited the β→α transformation. The kinetics of the transformation are largely determined by the nucleation of α-Sn.

Investigation of magnetic properties of FeCoAlON thin films with stripe domain structure

The FeCoAlON thin films were prepared by magnetron sputtering. Effect of element addition of Al, O, and N on magnetic materials was studied. Experiment demonstrated that with increasing Al, O and N, the film structure changed from polycrystalline to amorphous, and the films showed soft magnetism. When N content in the film is high, the films show stripe domain structure. The condition and mechanism for the occurrence of stripe domain structure were discussed in detail, and we found that the frequency response of permeability of the films show characteristics of multi-peak resonance.

High-temperature oxidation of hot-dip aluminizing coatings on a Ti3Al–Nb alloy and the effects of element additions

Hot-dip aluminizing and interdiffusion treatment were used to develop TiAl3-rich coatings on a Ti3Al–Nb alloy. The addition of Si, Mn, or Ag to the coatings improves the thickness uniformity and reduces the formation of the through-thickness transverse cracks. The element additions promote the formation of dense and continuous Al2O3-rich scales during the high-temperature oxidation. A layered structure of Al2O3/TiAl3/(TiAl3+TiAl2)/TiAl/Ti-depleted alloy/alloy from the outside to the inside forms after oxidation at 900°C without changing the main body of the Si- or Mn-modified coating, and the Ag-modified coating develops a layered structure of Al2O3/TiAl3/(TiAl3+TiAl2)/(TiAl2+TiAl3)/TiAl/alloy.

Effects of Zn-In-Sn elements on the electric properties of magnesium alloy anode materials

A new magnesium alloy anode is based on an environmentally friendly electrode that contains none of mercury, lead and chromate, but it can enhance the electric properties of alloy significantly. Magnesium alloy adding eco-friendly elements Zn-In-Sn which was developed by orthogonal design were obtained by two casting methods. The effect of additive elements on performance of electrode material was studied. The effects of elements addition and casting method on electric properties and corrosive properties of Mg-Zn-In-Sn alloys were investigated by using electrochemical measurements, corrosive tests and observation of surface structure. The results show that Mg-Zn-In-Sn alloy anode has higher electromotive force and more stable work potential than that commercial magnesium alloy AZ91. It is suitable for anode material of magnesium battery for its small hydrogen evolution, less self-corrosion rate and easy to shed corrosive offspring off.

Effects of elemental additions (Si and Sb) on the ageing behavior of AZ91 magnesium alloy

Effects of Si and Sb additions on the ageing behavior of AZ91 alloy have been investigated. Additions of Si and Sb lead to the formation of thermally stable Mg 2Si and Mg 3Sb 2 intermetallic phases, respectively, which are stable even after solution treatment at 410 °C for 48 h. Ageing treatment of AZ91 alloy at 200 °C results in the formation of Mg 17Al 12 phases in two morphologies: (i) discontinuous and (ii) continuous. Further the results of the present study have shown that individual and combined additions of Si and Sb suppress the formation of discontinuous precipitate during ageing. Dense populations of continuous precipitates observed around the hard intermetallic phases reduce the amount of chemical driving force required for both the initiation and propagation of discontinuous precipitates. In spite of these observations, the hardness measurements of aged alloy samples indicate that the alloying additions do not improve the peak hardness of AZ91 significantly.

Effect of elements Zn, Sn and In on microstructures and performances of AZ91 alloy

A new magnesium alloy plate added elements Zn, Sn and In was manufactured by twin-roll continuous casting method to improve the precipitation of AZ91 alloy. The effects of elements addition and casting method on microstructure and mechanical properties of the Mg-Zn-In-Sn alloys were investigated by optical microscopy (OM), transmission electron microscopy (TEM), electron probe micro-analysis (EPMA), X-ray diffractometry (XRD) and energy dispersion spectrograph (EDS). The results show that the Mg-Zn-In-Sn alloy has higher tensile strength and better corrosion protection than the AZ91 alloy. The outstanding precipitation strengthening effect of the alloy is attributed to the small grain size and the hard precipitates between the grain boundaries.

Effect of elements addition on hydrogen permeability and ductility of Nb40Ti18Zr12Ni30 alloy

Abstract Nb40Ti18Zr12Ni25M5 (M = Al, Co, Cu or Pd) alloys were prepared by arc melting in a purified argon atmosphere. Microstructures, ductility, hydrogen permeability (Φ) and activation energy Ea for hydrogen permeation of these alloys have been investigated by scanning electron microscopy (SEM), cold-rolling and a gas permeation technique, respectively. Although both Nb40Ti18Zr12Ni25Al5 and Nb40Ti18Zr12Ni25Pd5 alloys were brittle in the as-cast state, they were hydrogen permeable. Both Nb40Ti18Zr12Ni25Cu5 and Nb40Ti18Zr12Ni25Co5 alloys showed good ductility, which was meaningful to decrease the thickness by cold-rolling. The values of Φ673 K for the Nb40Ti18Zr12Ni25Al5 and the Nb40Ti18Zr12Ni25Co5 alloys at 673 K were 3.73 × 10−8 and 3.82 × 10−8 [mol H2 m−1 s−1 Pa−1/2], which were higher than that of the base one (Nb40Ti18Zr12Ni30 alloy). On the other hand, Cu and Pd showed little effect on hydrogen permeability. The Nb40Ti18Zr12Ni25Co5 alloy showed the highest hydrogen permeability, ductility and resistance to the hydrogen embrittlement among the alloys investigated in the present work. This alloy is a promising hydrogen permeable membrane.

Magnetic properties and phase evolution of direct-quenched (Co 40Fe 22Nb 6Zr 2B 30) 98M 2 (M=Cr, Cu, Sn, Dy, Pr, and Ta) ribbons with crystallization treatments

The effects of element addition in melt spun (Co 40Fe 22Nb 6Zr 2B 30) 98M 2 ribbons on magnetic properties have been investigated. In general, high crystallization degree of element additions results in high-saturated magnetization ( M s). In this study, the additions of Cr and Cu increase their crystallization temperatures and cause high M s's, while the additions of Sn, Dy, Pr, and Ta reduce their M s's. The structure evolution from element additions demonstrates that the crystallization degree and the existence of extra Fe-based phase are strongly related to the final magnetic properties.

Microstructure and mechanical properties of in situ Al–Mg2Si composites

In situ metal matrix composites (MMCs) with Mg2Si particulate reinforcement have been developed recently as ultralight materials. In this paper, a brief overview of the physical and mechanical properties of Mg2Si and the current status of research on Mg2Si reinforced MMCs is presented, followed by more detailed information on recent progress in the research group of the present authors. The effects of element additions and processing parameters on the microstructure of the composites obtained by gravity casting are discussed, together with some mechanical property data.

Effect of element additions on wear property of eutectic aluminium-silicon alloys

The effects of cerium, zinc and zirconium additions and subsequent heat treatment on wear of the eutectic aluminium-silicon alloys have been investigated in dry sliding against a steel counterface by using a pin-on-disc machine. Wear surfaces and debris were examined by scanning electron microscopy. Wear characteristics of both binary Al-Si alloys and a commercial LM 13 alloy, were also studied and compared with those of the AlSi alloy containing the Ce, Zn and Zr. The k-values of the ALSI (Al-12.3%Si), LM13, ASMC-1 (Al-12.3%Si-0.75%Mg-0.26%Ce) and ASMC-1 (heat-treated) obtained are 5.795 × 10 −4, 4.750 × 10 −4, 4.311 × 10 -4 and 3.981 × 10 −4 mm 3N −1 m −1, respectively.

非希土類酸化物高温超伝導体への異種元素添加効果

Effect of element addition on the superconductivity of rare-earth-element-free high Tc superconductors has been investigated. The element was chosen out of the IIa group. The measurement of the superconductivity revealed that the addition of the appropriate amount of Mg together with Cu was effective to rise the zero-resistance temperature of the Bi compounds.