scholarly journals Investigating the Linear Thermal Expansion of Additively Manufactured Multi-Material Joining between Invar and Steel

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5683
Author(s):  
Alexander Arbogast ◽  
Sougata Roy ◽  
Andrzej Nycz ◽  
Mark W. Noakes ◽  
Christopher Masuo ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Laser System ◽  
Linear Thermal Expansion ◽  
Base Plate ◽  
Small Deviations ◽  
Material Part ◽  
Material Specimen ◽  
Steel Base ◽  
A36 Steel

This work investigated the linear thermal expansion properties of a multi-material specimen fabricated with Invar M93 and A36 steel. A sequence of tests was performed to investigate the viability of additively manufactured Invar M93 for lowering the coefficient of thermal expansion (CTE) in multi-material part tooling. Invar beads were additively manufactured on a steel base plate using a fiber laser system, and samples were taken from the steel, Invar, and the interface between the two materials. The CTE of the samples was measured between 40 °C and 150 °C using a thermomechanical analyzer, and the elemental composition was studied with energy dispersive X-ray spectroscopy. The CTE of samples taken from the steel and the interface remained comparable to that of A36 steel; however, deviations between the thermal expansion values were prevalent due to element diffusion in and around the heat-affected zone. The CTEs measured from the Invar bead were lower than those from the other sections with the largest and smallest thermal expansion values being 10.40 μm/m-K and 2.09 μm/m-K. In each of the sections, the largest CTE was measured from samples taken from the end of the weld beads. An additional test was performed to measure the aggregate expansion of multi-material tools. Invar beads were welded on an A36 steel plate. The invar was machined, and the sample was heated in an oven from 40 °C and 160 °C. Strain gauges were placed on the surface of the part and were used to analyze how the combined thermal expansions of the invar and steel would affect the thermal expansion on the surface of a tool. There were small deviations between the expansion values measured by gauges placed in different orientations, and the elongation of the sample was greatest along the dimension containing a larger percentage of steel. On average, the expansion of the machined Invar surface was 42% less than the expansion of the steel surface. The results of this work demonstrate that additively manufactured Invar can be utilized to decrease the CTE for multi-material part tooling.

Tangguh LNG Project Statistical Young’s Modulus and Thermal Expansion Coefficient Testing of Clad Pipe Specimens

2011 ◽  
Author(s):  
Terry Griffiths ◽  
Isabel Hadley ◽  
Richard Johnson ◽  
Fabio Micari
Keyword(s):  
Thermal Expansion ◽  
Young’S Modulus ◽  
Room Temperature ◽  
Structural Reliability ◽  
Coefficient Of Thermal Expansion ◽  
Young's Modulus ◽  
Linear Thermal Expansion ◽  
Upheaval Buckling ◽  
Analysis Of Results ◽  
Mean And Variance

Material testing was undertaken on samples taken from clad pipe manufactured by JSW for the Tangguh LNG project. The test programme involved testing Young’s Modulus (E) and Coefficient of Linear Thermal Expansion (α) from room temperature to above 110° on each layer. This paper summarises testing and analysis of results which enabled mean and variance on each material property to be found. Checks were also undertaken for any correlations in properties between clad and parent layers, and between Young’s Modulus and Coefficient of Thermal Expansion. Analysis results are compared to existing industry norms and their implications for the Tangguh project UHB (Upheaval Buckling) SRA (Structural Reliability Analysis) are summarised.

Calculation of Defect Formation Energy from the Thermal Expansion Data for Lead Fluoride

1994 ◽  
Vol 369 ◽  
Author(s):  
Brenda J. Schuler ◽  
T. S. Aurora ◽  
D. O. Pederson ◽  
S. M. Day
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Formation Energy ◽  
Defect Formation ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Lead Fluoride ◽  
Defect Formation Energy ◽  
Thermal Expansion Data

AbstractLead fluoride is a superionic conductor with the fluorite structure. Results of the measurement of linear thermal expansion of lead fluoride (reported earlier in literature) showed a large increase in the thermal expansion coefficient near 700 K where the ionic conductivity has been shown to exhibit a sharp increase. It is believed that thermally-generated defects in a crystal lattice affect the thermal expansion coefficient. This idea was applied in the present analysis to calculate the defect formation energy (Ef) by using the literature values of the coefficient of thermal expansion. It was assumed that the thermal expansion in excess of that produced due to the lattice anharmonicity (δ∝) is proportional to the concentration of defects (n). With this assumption, one may write: δ∝ = c nº exp(-Ef/kT), where c is a constant. For lead fluoride, a plot of ln(δ∝) versus (l/T) yielded Ef = 0.56 eV which is lower than the literature values. The assumptions in this analysis and the discrepancy in the result are discussed.

scholarly journals Thermal analysis of metal-ceramic bonding using finite element method

2014 ◽  
Vol 3 (2) ◽  
pp. 216 ◽  
Author(s):  
S. Gopinath ◽  
R Sabarish ◽  
R. Sasidharan
Keyword(s):  
Finite Element ◽  
Thermal Expansion ◽  
Thermal Stress ◽  
Bonding Strength ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Processing Temperature ◽  
Element Analysis ◽  
Metal Ceramic ◽  
The Difference

This paper reports a finite element study of effect of bonding strength between metal and ceramic. The bonding strength is evaluated with different processing temperature and holding time. The difference between the coefficients of linear thermal expansion (CTEs) of the metal and ceramic induces thermal stress at the interface. The mismatch thermal stress at the interface region plays an important role in improving bonding strength. Hence, it is essential to evaluate the interface bonding in metal-ceramics joints. The Al/SiC bonding was modeled and analyzed using finite element analysis in ANSYS (v.10). Keywords: Bonding Strength, Coefficient of Thermal Expansion, Thermal Stress, Interface, Al/Sic, FEA.

Effect of aggregate type on linear thermal expansion of self-consolidating concrete at elevated temperatures

2012 ◽  
Vol 19 (3) ◽  
pp. 259-269 ◽  
Author(s):  
Tayfun Uygunoğlu ◽  
İlker Bekir Topçu
Keyword(s):  
Thermal Expansion ◽  
Thermal Properties ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Thermal Tests ◽  
Linear Change ◽  
Volcanic Tuff ◽  
Self Consolidating Concrete ◽  
Cement Ratio

AbstractIn this study, the effects of aggregate type on the coefficient of thermal expansion of self-consolidating concrete (SCC) produced with normal and lightweight (porous) aggregate (SCLC) were investigated. In experiments, three aggregate types, gravel, volcanic tuff, and diatomite, were used. Different combinations of water/cement ratio and superplasticizer dosage levels were prepared for the SCC and SCLC mixtures. Thermal tests were performed to accurately characterize the coefficient of thermal expansion (CTE) of SCC and SCLC aged 28 days using the dilatometer. The CTEs of SCC and SCLC were defined by measuring the linear change in length of concrete specimens subjected to a range of temperatures from 20°C to 1000°C. The results, in general, showed that SCLC has a lower CTE than that of SCC above 100°C. Moreover, CTE values of SCC and SCLC were decreased with increase in porous structure. The aggregate type has significant influence on the thermal properties of SCC.

scholarly journals Mechanical Testing of Recycled HDPE Extruded Hollow Section

2020 ◽  
Vol 4 (2) ◽  
pp. 112-121
Author(s):  
Greg Wheatley ◽  
Rendage Sachini Sandeepa Chandrasiri
Keyword(s):  
Thermal Expansion ◽  
Yield Strength ◽  
Ultimate Strength ◽  
Modulus Of Elasticity ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Environmental Benefits ◽  
Hollow Section ◽  
Significant Difference ◽  
Recycled Hdpe

High density polyethylene (HDPE) is a thermoplastic polymer which is classified as one of the highly consumed types of plastics. One major advantage of thermoplastic materials is their ability of recycling and reprocessing which will bring considerable economicand environmental benefits. The present paper, therefore, endeavours to explore the practical possibility of using recycled HDPE hollow section as a replacement of virgin HDPE made by the extrusion process. The main focus of the study was to evaluate the mechanical performance of the recycled HDPE and compare the results with virgin or non-recycled HDPE.  The modulus of elasticity, tensile yield and ultimate strength, compressive yield and ultimate strength, flexural yield and ultimate strength and the coefficient of thermal expansion were the main parameters to be checked against the respective mechanical properties. Thus, pursuant to the rsults, it was found out  that the modulus of elasticity and the tensile yield strength are lower in recycled HDPE compared to the non-recycled HDPE. However, there is no significant difference between the recycled and non-recycled HDPE for the tensile ultimate strength, compressive yield strength and compressive ultimate strength. The flexural yield strength and flexural ultimate strength properties of the recycled HDPE proved to be superior to those of the non-recycled HDPE. The coefficient of linear thermal expansion of the recycled HDPE sample was 130 μm/(m.°C) and that for the non-recycled HDPE was 142 μm/(m.°C).

scholarly journals The Structure, Vibrational Spectra, and Thermal Expansion Study of AVO4 (A=Bi, Fe, Cr) and Co2V2O7

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1628 ◽  
Author(s):  
Xiaoke He ◽  
Chenjun Zhang ◽  
Ding Tian
Keyword(s):  
Thermal Expansion ◽  
Room Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Monoclinic Structure ◽  
Functional Material ◽  
Temperature Dependent ◽  
Vanadium Compounds ◽  
Measurement Results ◽  
Thermal Expansion Study

Vanadate is an important functional material. It has been widely studied and applied in luminescence and photocatalysis. Vanadium compounds have been synthesized to investigate the thermal expansion properties and structure. Both BiVO4 and Co2V2O7 are monoclinic at room temperature, FeVO4’s crystal structure is triclinic, and CrVO4 is orthorhombic. The relatively linear, thermal-expansion, and temperature-dependent Raman spectroscopy results showed that the phase transition of BiVO4 occurred at 200 to 300 °C. The coefficient of thermal expansion (CTE) of Co2V2O7 was larger than that of the monoclinic structure BiVO4. The CTE of the tetragonal structure of BiVO4 was 15.27 × 10−6 °C−1 which was the largest CTE in our measurement results, and the CTE of anorthic structure FeVO4 was 2.84 × 10−6 °C−1 and was the smallest.

THE COEFFICIENT OF THERMAL EXPANSION OF VARIOUS CUBIC METALS BELOW 100 °K

1965 ◽  
Vol 43 (2) ◽  
pp. 193-219 ◽  
Author(s):  
D. B. Fraser ◽  
A. C. Hollis Hallett
Keyword(s):  
Thermal Expansion ◽  
Noble Metals ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Electronic Contribution ◽  
Electronic Effects ◽  
Interferometric Method ◽  
Lattice Contribution ◽  
Cubic Metals ◽  
Fabry Perot

Measurements have been made of the coefficient of linear thermal expansion, α, of Cu, Ag, Au, Al, α-Fe, and Ni at temperatures below 100 °K using an interferometric method in which the spacer between the optical flats of a Fabry–Perot-type interferometer was made of the material studied. The lowest temperatures at which values of α are given are about 20 °K (Cu, Ag), 11 °K (Au), 25 °K (Al, Fe), and 32 °K (Ni). The results are discussed in terms of the Gruneisen parameter γ which, for Cu, Ag, and Au, is approximately constant at high temperatures, but tends to rise slightly as the temperature is reduced towards the lowest temperatures of measurement. For Al, a correction for the electronic contribution is applied below 40 °K to deduce the lattice contribution γL, which rises more spectacularly at low temperatures than the results for the noble metals. For Fe, separation of α into two contributions, one from the lattice and one from the combined magnetic and electronic effects, may be made, giving γL = 1.45; the combined magnetic and electronic contribution is very small.

scholarly journals Transient Thermoelastic Analysis of a Cylinder Having a Varied Coefficient of Thermal Expansion

2020 ◽  
Vol 64 (4) ◽  
pp. 273-278
Author(s):  
Olga Shypul ◽  
Vitalii Myntiuk
Keyword(s):  
Heat Flux ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Transient State ◽  
Maximum Temperature ◽  
Stress Distributions ◽  
One Dimensional ◽  
The One ◽  
Transient Thermal

This paper is concerned with the mathematical modeling of transient thermal elastic problem involving a layered cylinder with a varied coefficient of thermal expansion and powered by a heat flux from an external surfaces. All material's properties are the same for each cylinder's layers, besides the coefficient of linear thermal expansion which is varied and corresponds to hardened and unhardened layers. An obtained solution is a transient state of a heat transfer for the one-dimensional temperature change under the action of heat flux in continuous time. Cumbersome analytical solutions are converted into simple approximation. They are used to solve the inverse problems of the thermal stressed state–determining the time of action of the heat flux to achieve the specified maximum temperature or stress. Some numerical results for the stress distributions are shown in figures.

Thermal Expansion of Lithium Sulphate

1968 ◽  
Vol 23 (9) ◽  
pp. 1259-1261 ◽  
Author(s):  
Bengt Augustsson ◽  
Alf Ekhed
Keyword(s):  
Thermal Expansion ◽  
Monoclinic Phase ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Temperature Curve ◽  
Cubic Phase ◽  
Linear Coefficient ◽  
Cubic Phases ◽  
Lithium Sulphate ◽  
Good Agreement

The coefficient of linear thermal expansion has been measured for polycrystalline Li2SO4. Between 200 and 550 °C (monoclinic phase) the average linear coefficient of thermal expansion was determined to (22 ± 1) x10-6 degr.-1, and for the range 600—750 °C (cubic phase) the coefficient (43 ±3)x 10-6 degr.-1 was obtained. The quoted errors are standard deviations.The volume change at the transition between the monoclinic and cubic phases was found to be 2.2 cm3/mole, which is in good agreement with Pistorius’ estimation from the pressure-temperature curve of this transition.

Mechanical and thermal properties of combustion-synthesized perovskites, La1−xSrxCr0.2Fe0.8O3

2001 ◽  
Vol 16 (12) ◽  
pp. 3545-3553 ◽  
Author(s):  
Yeong-Shyung Chou ◽  
K. Kerstetter ◽  
L. R. Pederson ◽  
R. E. Williford
Keyword(s):  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Mechanical And Thermal Properties ◽  
Flexure Strength ◽  
Linear Coefficient ◽  
Shear Moduli ◽  
Critical Flaw ◽  
Microhardness Indentation ◽  
Biaxial Flexure

This paper examined the room-temperature thermal and mechanical properties of a mixed conducting perovskite La1−xSrxCr0.2Fe0.8O3 (x = 0.2 to 0.8). Powders were made by the combustion-synthesis technique and sintered at 1250 °C in air. Sintered density, crystal phase, and grain size were characterized. Linear thermal expansion in air was also tested. Young's and shear moduli, microhardness, indentation fracture toughness, and biaxial flexure strength were determined. It was found that the linear coefficient of thermal expansion increased with increasing Sr content, while elastic modulus appeared to decrease with increasing Sr content. Young's modulus of 128 to 192 GPa and shear modulus of 51 to 74 GPa were measured. A biaxial flexure strength of 243 MPa was measured for the lowest Sr content batches. Batches with higher Sr concentrations (x = 0.6 to 0.8) showed extensive cracking. Indentation toughness showed a decrease with increasing Sr content. In addition, fractography was used to characterize the critical flaw and the fracture mode.

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