Study of Non-Homogeneity of Magnetic Field Distribution in Single-Crystal Ni-Mn-Ga Magnetic Shape Memory Element in Actuators due to its Anisotropic Twinned Microstructure

Magnetic shape memory (MSM) alloys are relatively new and very promising “smart” materials which respond to magnetic fields and exhibit the shape memory effect at room temperature. Maximum strain varies from 6 to 12% of the MSM element’s length depending on its microstructure. The shape memory effect and magnetic field-induced reorientation of MSM twin variants in low-temperature martensite phase are subject to an ongoing research for almost two decades. However, the magnetic field distribution in the MSM elements and effects of its varying magnetic permeability on bias magnetic field are not well studied. In this paper we present an extension to the existing modeling approach for MSM elements applicable to actuator design. The effects arising from single-crystal anisotropy and demagnetization effects due to non-homogeneous multi-variant MSM microstructure are studied and discussed. The proposed approach is validated by comparing computational results with previously reported measurement data

Simulation-based Design Methodology for Magnetic Shape Memory Actuators

MSM alloys, especially Ni-Mn-Ga alloys have been studied extensively for almost two decades. Their remarkable properties make them very promising for use in various electromagnetic (EM) devices, notably in actuators and sensors. However, at present there are no well-established design methodologies for MSM-based devises. This paper proposes a design methodology that uses commercially available EM modelling software and just a small amount of experimental data for its implementation. It allows reliable actuator modelling and performance evaluation without needing to calculate the magnetic field-induced stresses

Electromagnetic and thermal analyses of high performance magnetic shape memory actuators for valve applications

Magnetic shape memory (MSM) alloys are relatively new “smart” alloys which have enormous potential to be used in actuators, sensors and other electrical devices. Their large strain and considerable stress output can be controlled by magnetic fields or mechanical stresses. Maximum magnetic field-induced strain varies from 6 to 12% of the MSM element’s length depending on its microstructure. However, very low operational temperature limit is one of the main drawbacks of conventional MSM alloys. This makes their application in high performance actuators challenging due to considerable power losses. This paper discusses different MSM actuator designs optimized particularly for large force output for pneumatic electromagnetic (EM) valve applications. The thermal problem is addressed through analyzing the heat transfer conditions of each particular design and the effects of different cooling systems. An energy-efficient operating cycle for varying actuator load that takes advantage of the shape memory effect is also proposed. This allows minimization of energy losses resulting in acceptable increase in temperature ensuring stable continuous actuation

Melting of ferrosilicon manganese with the use of high ash rock coal as a reducing agent

A study of the process of smelting ferrosilicon manganese with the use of high ash rock coals as a reducer instead of traditional coke was carried out. The physicochemical properties of coke from high-ash coals of the Kuu-chek deposit have been studied. The fundamental possibility of its application for the production of standard ferrosilicon manganese in large-scale laboratory conditions has been shown

Study of magnetic field distribution in anisotropic single twin-boundary magnetic shape memory (MSM) element in actuators

Magnetic shape memory effect exhibited by certain alloys at room temperature is known for almost 20 years. The most studied MSM alloys are Ni-Mn-Ga alloys which exhibit up to 12% magnetic field-induced strain (change in shape) depending on microstructure. A multibillion cycle operation without malfunction along with their "smart" properties make them very promising for application in electromagnetic (EM) actuators and sensors. However, considerable twinning stress of MSM crystals resulting in magneto-mechanical hysteresis decreases the efficiency and output force of MSM actuators. Whereas twinning stress of conventional MSM crystals has been significantly decreased over the years, novel crystals with Type II twin boundaries (TBs) possess even lower twinning stress. Unfortunately, the microstructure of MSM crystals with very low twinning stress tends to be unstable leading to their rapid crack growth. Whilst this phenomenon has been studied experimentally, the magnetic field distribution in anisotropic single twin-boundary MSM elements has not been considered yet. This paper analyses the magnetic field distribution in two-variant single twin-boundary MSM elements and discusses its effects on magnetic field-induced stress acting on the twin boundary

Melting of high-carbon ferrochrome using coal of the saryadyr deposit

The article presents the results of large-scale laboratory tests on the smelting of high-carbon ferrochrome with the replacement of parts metallurgical coke with high-ash coal from the Saryadyr deposits. According to the test results, it can be stated that the optimal percentage of replacing metallurgical coke with high-ash Saradyr coal is 30 – 40 %. During a large-scale laboratory test, it was also established that the cost of the alloy was reduced due to the partial replacement of expensive coke and removes the fluxing component of quartzite from the charge composition, and improves the TPE of the high-carbon ferrochrome smelting process

Microscopic and Dynamical Properties of ICF/WDM Plasmas

Investigation of physical properties of dense plasmas is one of the important topics in the physics of inertial confinement fusion, warm dense matter and high-power lasers physics. Due to the big difference between the mass of ions and electrons the considered plasma is dense and non-isothermal. It is known that the interaction potentials between particles are also of importance for correctly calculation of plasma properties taking into account peculiarities and parameters of investigated plasma [1]..

Microscopic and Dynamical Properties of ICF/WDM Plasmas

Investigation of physical properties of dense plasmas is one of the important topics in the physics of inertial confinement fusion, warm dense matter and high-power lasers physics. Due to the big difference between the mass of ions and electrons the considered plasma is dense and non-isothermal. It is known that the interaction potentials between particles are also of importance for correctly calculation of plasma properties taking into account peculiarities and parameters of investigated plasma [1]..

Experimental study of energy distribution in ion-beam lithography

The paper reports two important results. Conducted a rigorous comparison of the sensitivity of the resist is polymethylmethacrylate (PMMA) to the irradiation of electron and ion beams. It is shown that, as in the case of electron irradiation, the resist shows both positive (at low doses) and negative (at higher doses) behavior of sensitivity. But compared with the electronic exposure, sensitivity of the resist is approximately a thousand times higher to the ion exposure, both the positive and negative areas....