Alloys In Liquid State Research Articles

In situ control of the distributions of alloying elements in alloys in liquid state using high magnetic field gradients

In this work, Mn–Sb alloys were melted and held in various magnetic field gradients for various times. The corresponding distributions of the alloying elements in the alloys in liquid state were revealed by a quenching method. It was found that the primary MnSb showed a relatively uniform distribution in the alloy quenched in the magnetic field gradient of B d B/d z=0 T 2/m, while it was mainly distributed in the lower and upper part of the alloys quenched in negative and positive magnetic field gradients, respectively. The experimental results show that it is possible to in situ control the distributions of alloying elements in alloys in the liquid state using high gradient magnetic fields if there is a difference in magnetic susceptibility.

Measurement and Analysis of Liquid Density of NiCoAlMo Quarternary Alloys

Abstract The density of liquid NiCoAlMo quaternary alloy with a fixed molar ratio of Ni:Co:Al (xNi:xCo:xAl≈73:12:15) which is close to the average value of the commercial Ni-based superalloys TMS75, INCO713, CM247LC and CMSX-4, and molybdenum concentration change from 0% to 10% (mass fraction) was measured by a modified sessile drop method. It is found that the density of the liquid NiCoAlMo quaternary alloy decreases with increasing of temperature, but increases with the increase of molybdenum concentration in the alloys. The molar volume of liquid NiCoAlMo quaternary alloy increases with the increase of temperature and molybdenum concentration, and shows a negative deviation from the ideal linear mixing. The liquid density of NiCoAlMo quaternary alloy calculated from the partial molar volumes of nickel, cobalt, aluminum and molybdenum in the corresponding Ni-bases binary alloy are in good agreement with the experimental results; it means that within the error tolerance range the density of liquid Ni-based multi-component alloys can be predicted from the partial volumes of elements in Ni-based binary alloys in liquid state.

Structure factors of binary liquid metal alloys within the square-well model

Abstract The procedure suggested previously for the description of the square-well (SW) fluid within the framework of the mean spherical approximation is applied to calculate the structure factors of pure Na, pure K, and 0.5Na-0.5K alloy in liquid state. It is shown that our variations of the SW depth and SW width enable us to achieve a good agreement between calculated and experimental structure factors. The procedure under consideration gives more accurate results than the random phase approximation for the same values of the SW parameters.

Injectable liquid alkali alloy based-tumor thermal ablation therapy

The alkali metal was recently found to be a very useful agent for inducing minimally invasive tumor hyperthermia therapy. However, the solid-like metal makes it somewhat inconvenient to perform the surgery. Here, to overcome this drawback, the NaK alloy in liquid state at room temperature was proposed as a highly efficient thermal ablative agent for tumor treatment. For illustration purposes, the functionalized liquid NaK alloy at a mass ratio 1:1 was obtained and an amount of 0.35ml was injected into in vitro pork. The sizes of the damage region and temperature response were measured. It was found that significant temperature increase by a magnitude of > 80°C can easily be obtained. This produced a large coagulation and necrotic area within selected areas for in vitro tests and the necrotic region volume is three times that of the NaK injection quantity. Furthermore, for the in vivo experiment, breast EMT6 tumor in mouse was subjected to treatment by NaK alloy. Tumor was harvested after the experiment to assess its viability. Histological section showed complete necrosis at the target site. These conceptual results demonstrate that using injectable liquid alkali alloy to ablate tumor is rather promising. This study also raised interesting issues waiting for clarification in future technical and animal studies aiming to assess efficacy, side effects and safety of the new therapy.

Physical properties of the liquid Pd–18 at.% Si alloy

The temperature dependence of the density, the viscosity, the ultrasound velocity and attenuation and the magnetic susceptibility of the Pd–18at.% Si alloy in liquid state have been measured. A difference during heating and subsequent cooling with a branching temperature at 1380–1430K was observed for all measured quantities. An abnormally high attenuation of ultrasound was furthermore observed during several hours after that the sample was melted. The results are interpreted in terms of metastable inhomogeneities existing in the melt.

Density of liquid NiCrAlMo quarternary alloys measured by a modified sessile drop method

The densities of liquid NiCrAlMo quaternary alloys with a fixed molar ratio of Ni:Cr:Al (approximately as 73:14:13) and molybdenum concentration from 0 to 10 mass% were measured by a modified sessile drop method (MSDM). It was found that the density of the liquid NiCrAlMo quaternary alloys decreases with increasing temperature, but increases with the increase of molybdenum concentration. The molar volume of liquid NiCrAlMo quaternary alloys increases with the increase of temperature and molybdenum concentration. The density of liquid NiCrAlMo quaternary alloys calculated from the partial molar volumes of nickel, chromium, aluminum and molybdenum in the corresponding Ni-based binary alloys are in good agreement with the experimental results, means, within the error tolerance range the density of liquid Ni-based multi-component alloys can be predicted from the partial volumes of elements in Ni-based binary alloys in liquid state.

Study of Grain Refinement and SiC Nanoparticle Reinforced Magnesium Alloys

Magnesium alloys offer advantages of low density, high specific strength, machinability and availability. So it has been used more and more in many fields, such as automobile, communication etc. In this paper, grain refinement process and SiC nanoparticles reinforcement process are investigated for the purposes of increasing ultimate tensile strengthen and ductility of AM60B magnesium alloys. We find that after grain refinement process the ultimate tensile strength of AM60B alloys with permanent casting increase to 241MPa, which is about 27MPa higher than that of original alloys, and the elongation of it increases up to 20.1%, which is about 8.7% higher than that of original alloys. We added SiC nanoparticle into AM60B alloys in liquid state and found it could increase strength and ductility of alloys. By SiC nanoparticle reinforced process the ultimate tensile strength of magnesium alloys can increase up to 255MPa with the elongation of 19%.

Structure of molten copper–germanium alloys

Copper–germanium alloys in liquid state at 1373 K have been investigated. Non-linear behaviour of the structure-sensitive parameters and electrical resistivity of the alloys versus concentration have been observed. Close relation between the crystal structure and the local ordering in molten Cu–Ge alloys has been found. The inhomogeneous structure of the liquid Cu–Ge alloys at a microscopic level was established. Melts are shown to contain clusters from pure components and clusters with composition corresponding to that of the intermetallic compound Cu 3Ge existing in the solid phase.

Measuring Magnetic Susceptibility of Undercooled Co-Based Alloys with a Faraday Balance

Co-based melts embedded by glass flux in a crucible can be undercooled nearly as strong as samples processed containerlessly by electromagnetic levitation. This allows to measure magnetic susceptibility on undercooled melts while combining the Faraday method with undercooling technique. The magnetic susceptibility of Co and Co-based alloys will be analysed as a function of temperature from superheated to undercooled state. This will be performed by measuring the change of magnetic force F Z on a sample in a constant magnetic field H 0 and an additional gradient field by means of a Faraday balance. When liquid Co-based alloys are undercooled the magnetisation steeply rises if temperature approaches the Curie temperature. The magnetisation is measured for some Co-based alloys in liquid state as function of alloy system and its concentration. The results show that the magnetic susceptibility of the liquid undercooled samples follows a Curie-Weiss behaviour, from which Curie temperature is inferred.

Electrical and thermal conductivity of A319 and A356 aluminum alloys

A rotational contactless inductive measurement technique has been used to measure the electrical resistivity of A319 and A356 aluminum alloys at both solid and liquid states. The method is based on the phenomena that when a conducting material rotates in a magnetic field, circulating eddy currents are induced and generate an opposing torque, which is proportional to the electrical conductivity of the material. The technique was checked and calibrated with pure aluminum where considerable electrical resistivity data exist in the literature. Wiedemann-Franz-Lorenz law was used to estimate the thermal conductivity of A319 and A356 aluminum alloys in liquid state.

Quality control of production of alloys in liquid state by laser spectroscopy

Due to the important economical advantages, laboratory investigations of pre¬liminary character have been performed aimed at direct analysis of molten metals with¬out sample taking. The optimisation procedure for the application of the laser-induced breakdown spectroscopy (TRELD3S) has been described According to the results achieved, the method can be successfully applied for the analysis of aluminium and zinc- alloy melts.Accuracy, repeatability meet the requirements of the metallurgical process-control and is not superseded by the traditional spectrometry analytical methods.

Radiative properties of transition metals and alloys in liquid state.

1450～1850Kの高温で液体状態にあるニッケル,鉄,硬鋼,鋳鉄,ステンレス網の赤外ふく射率の分光測定を行った.スペクトルは赤外長波長側ではDrude形伝導電子吸収型のものとなる.ニッケル以外の金属では近赤外域に可視域の帯間遷移吸収の効果がおよぴ,そこでふく射率は温度の増加とともに減少する.これらの性質を考慮して遷移金属の液体状態のための光学定数分散式を示し,また半球ふく射率,全ふく射率などを計算した.

Magnetic susceptibility of gallium-indium alloys in liquid state

Magnetic susceptibility of gallium-indium alloys in liquid state

Densities of Binary Copper Based Alloys in Liquid State

This study was carried out to investigate the physical properties of binary copper based alloys in the liquid state. Densities of Cu–Sn, Cu–Fe, Cu–Co and Cu–Ni alloys were measured by the maximum bubble pressure method at temperatures between their melting points and 1650°C. The behavior of molar volume of these alloys did not indicate that of ideal mixing. The deviation of molar volume from ideal mixing was positive in the case of Cu–Fe and Cu–Co alloys and negative in the case of Cu–Sn alloy, and the deviation in Cu–Ni alloy changes from positive to negative with increase in temperature. In the case of Cu–Sn alloy, assuming the presence of clusters in the liquid, the physical properties were discussed.

Densities and Viscosities of Iron, Cobalt and Fe–Co Alloy in Liquid State

This study was carried out to investigate the physical properties of Fe–Co alloy. Densitiy measurements were made by the maximum bubble pressure method at temperatures between the melting points and 1660°C, and viscosity measurements by the oscillating crucible method at temperatures between the melting points and 1760°C.The molar volume did not indicate the behavior of ideal mixing. The viscosity isotherm showed a maximum at about 50 at% Co. By comparing these phenomena with some other physical properties, it was discussed that this maximum might be attributed to, the presence of clusters in the liquid.

Densities of Fe–Ni, Co–Ni, Co–Mo and Co–W Alloys in Liquid State

Densities of Fe–Ni, Co–Ni, Co–Mo and Co–W Alloys in Liquid State