Liquid Level Sensor for High Temperature Molten Salt in Confined Container

Electrical resistance measurements on different rod materials in liquid solutions, molten salts, or molten lead are considered to design a liquid level sensor in a sealed containers when the temperature of the fluid is very high (~1000ºC) and conventional measurements are not possible due to properties of the fluid or condition of the container. An analytical solution to the problem is adopted to reduce the cost of the sensor and overcome the difficulties of calibration of sensors at high temperature for prediction of the level of liquid. An electrical circuit model is suggested for analytical solution to compute the resistivity versus height of the electrode rod submerged in the liquid in a narrow container. Good prediction of circuit model for experimental results is verified by comparison of analytical results of different combination of liquid solutions and rods’ material with experimental graphs

Metrology and microscopy analysis of multisheet packs manufactured via superplastic forming to study possible diffusion bonding

A number of titanium alloys multisheet packs with predefined complex features were manufactured via superplastic forming (SPF) and investigated via metrology and microscopy analysis to determine the possible occurrence of diffusion bonding. Four sheets of titanium alloys were welded using resistance seam welding based on a defined pattern to manufacture a composite sheet of four layers. Each composite sheet structure was composed of four sheets: two core sheets of the same titanium alloy material - Ti64 or Ti54M, and two external sheets of similar titanium alloy material - Ti64 or Ti6242. The composite sheet structures were inflated via SPF process in pockets where the sheets were not welded to each other to form a complex component. A pressure cycle was determined via the analysis of the numerical data from finite element simulations and a laboratory optimization method to form each multisheet pack. The maximum elongation due to stretching of sheets by SPF could reach 134% of initial part pre-forming. The wall thickness of each inflated packs was measured via GOM scanning all features of the formed structures. The thickness reduction imposed by SPF to the component surfaces was found to be up to 59% at some regions of the packs. Several samples from selected regions of each inflated pack were investigated via scanning electron microscopy (SEM) to study whether diffusion bonding occurred between the sheets. The GOM scanning and image analysis demonstrated that during SPF, the multisheet packs underwent a degree of diffusion bonding where the adjacent sheets exhibited thickness reduction under compression forces

Computing strain rate sensitivity of aluminium alloy 1050

The strain rate sensitivity of commercial aluminium alloy 1050 (or AA1050) was calculated using uniaxial tensile test results. The experimental data were collected from hot uniaxial tensile test carried out according to E-2448 standard at different strain rates and testing temperatures. The results were analysed to approximate the optimum value of strain rate sensitivity (m-value) for commercial AA1050 tempering H14 with no additional heat treatment or microstructure altering. The strain rate sensitivity was determined by implementing the uniaxial tensile test data in creep law and by plotting the strain rate-flow stress curve. The formulation of the problem was demonstrated for Bailey-Norton law time hardening and strain hardening governing equations. The results presented low strain rate sensitivity of AA1050-H14 at 100 oC, 200 oC, 300 oC, and 500 oC for the selected pure plastic strains before necking zone. The maximum m-value for uniaxial tensile tests was found to be about the probe strain of 4% at 300 oC forming temperature under loading with the strain rate of 0.0005 s-1

Superplastic forming of 1050 aluminium alloy

Superplastic forming (SPF) was implemented to form aluminium alloy 1050H14 (AA1050H14) for industrial applications. A number of ABAQUS numerical simulations were developed to predict he formation behavior of the AA1050H14 sheet at different temperatures by embedding the built-in creep material model. The published data was deployed in the FEM models for AA1050 flow stress curves at different uniaxial loading strain rates and testing temperatures. The m-value of AA1050 was obtained from the previous publication. The AA1050 sheets were blown into the die cavity by hot gas pressure according to the extracted pressure cycles from the FEM outcomes. The simulation mimics the formation of the SPF part in the press for both geometrical and formation time, which in turn captures the material flow rate using the creep model. The elongation of AA1050 sheets via SPF is within the limitation reached in the uniaxial test rates published by the author but the lead time is suitable for forming AA1050 complex boxes used in the food industry or the relevant sectors

The Effect of Cooling Rate on the Microstructure Configuration of Continuously Cast Steel Slabs

This research work is another step for increasing the efficiency and productivity of the steel making process by enhancing both quality and quantity of the steel produced by the Continuous Casting process. When steels cool from a high temperature, austenite transforms into other phase configurations according to the austenite composition and cooling rate. As result of phase transformation, the steel crystal structure and, consequently, both the shape and the lattice parameter of the unit cell, change. These changes may introduce dilatational strains into the microstructure, which result in the creation of residual stress concentration zones within the microstructure. These stress concentration zones are vulnerable regions to the formation of microcracks or growth of the flaws in these regions. The main objective of this dissertation is to develop a method to define the optimum cooling rate for cooling continuously as-cast steel on industrial level. An FEM algorithm developed with the ANSYS codes is introduced in this dissertation to simulate the cooling of as-cast steel from any temperature below the solidification temperature. The algorithm is capable of being customized to simulate the thermodynamic behavior of as-cast steel microstructure with any chemical composition and any casting geometry imposed to desired cooling method. The phase transformation simulations were based on the CCT diagram and, therefore, they were quasi-real models. The models predict, analytically, the generation of the stress concentration regions due to the thermodynamic strains during cooling a sample from the austenite temperature range with different cooling rates. Another series of FEM models presented in this dissertation and post non-destructive tests (NDT) ultrasonic image analysis tests suggested in this work, can be used in the discussion of the effect of the cooling rate on the altering of the soundness of the tested steel. A combination of the suggested FEM algorithm and post image processing of NDT ultrasonic images along with laboratory cooling experiments and microstructural analysis provide a guideline to find the cooling rate for each grade of steel in the casting steel industry. Results of JMATPRO software also are deployed to increase the accuracy of the experimental set up and to obtain the required input data to run the proposed numerical algorithm cooling simulation

Studying the effect of hydroxyapatite particles in osteoconductivity of Ti-HA bioceramic

Ball milling method and powder metallurgy technology were employed to synthetize metal matrix composites (MMC) for bone grafts' applications. The raw powder of the MMC was prepared by mechanical alloying of pure titanium (Ti) powder with hydroxyapatite (HA) particles. The biocompatibilities of the sintered Ti-HA composites were examined after immersing the samples in simulated body solution (SBF) for different periods of time. SEM image and XRD results analysis were utilised to study the effect of HA on osteoconductivity of the Ti-HA composite. To this purpose, several composites were synthetized from different Ti-HA raw powder combination based on the HA particle size, milling time, and the mass fraction of HA content (% w/w) in the MMC. In-Vitro analysis of Ti-HA composite shows that composite with 30% w/w HA has higher bioactivity in comparison with composite containing pure Ti with 10% w/w HA

The UK Hydrogen Innovation Opportunity : Hydrogen Technology Roadmaps

This report provides an overview of cross-cutting hydrogen technology roadmaps. It has been produced as a supporting report to the UK Hydrogen Innovation Opportunity

Application of superplastic forming in manufacture four-sheet sandwich panel sheetstock

This presentation discusses the main processes of a superplastic forming (SPF) method to form a complex component with eight-pocket from a four-sheet sandwich panel sheetstock. Four sheets of titanium alloys were welded using resistance seam welding based on a defined pattern to manufacture a composite sheetstock of four layers. The composite sheet structures were inflated via SPF process using the Advanced Forming Research Centre’s 200 T SPF press in pockets where the sheets were not welded to each other to form a complex component. Each sheetstock was arranged to consist of four sheets: two core sheets from the same material, which create the inner structure of the panel, two skin sheets from the same material, which form the outer structure of the panel. Ti64 (Ti-6Al-4V) and Ti54 M (Ti-5Al-4Cr-4Mo-2Sn-2Zr titanium alloy sheets were used for the core sheets, whereas Ti64 and Ti6242 (Ti-6Al-2Sn-4Zr-2Mo) titanium alloy sheets were used for the outer sheets of the packs. I will also discuss the manufacture and assembly of the four-sheet packs, and briefly, explain the manufacturing processes adopted to manufacture the dies used in SPF trials. Furthermore, I will go through the applied methodology to define the SPF pressure-time curves to inflate the packs for two SPF gas feeding pipes at specific forming temperature and strain rate. Several samples from selected regions of each inflated pack were investigated via optical and scanning electron microscopy (SEM) to study whether diffusion bonding occurred between the sheets. The optical microscopy images were obtained for three different levels of magnification (x10, x20, and x50) for all samples. The GOM scanning and image analysis demonstrated that during SPF the multisheet packs underwent a degree of diffusion bonding where the adjacent sheets exhibited thickness reduction under compression forces. The thickness reduction to the component surfaces imposed by SPF was found to be up to 59% in some regions of the packs and the elongation was estimated to be up to 134%. The same procedure could be implemented to manufacture sandwich panels with more complex core configurations from sheetstock composed of more than three sheets and made of different titanium alloy

Reinforced Aluminum Matrix Composite Application in Friction Material

This article deals with the effective attributes of friction material application out of aluminum matrix composites (AMC) containing disperse ceramic phase, particularly SiC particles, via literature survey and result analyzing of the relevant research works. These properties include thermal expansion coefficient, wear, friction coefficient, mechanical and thermal strength, durability, etc. The wear mechanism of braking in brake pads is discussed to perceive the material behavior of the friction pad constituents and phases to ameliorate the vehicle’s brake pad performance considering its main tasks. The discussion elaborates the advantages and the disadvantages of AMC as friction material based on the essential brake pad properties defined by automotive standards parameters and the vehicle industries requirements. Analysis of the results presented in this paper suggests that the optimized reinforced AMC may result in a new patent for friction material applied in the vehicle brake pad