Dissimilar Materials Laser Welding Characteristics of Stainless Steel and Titanium Alloy

2013 ◽  
Vol 465-466 ◽  
pp. 1060-1064 ◽  
Author(s):  
Zazuli Mohid ◽  
M.A. Liman ◽  
M.R.A. Rahman ◽  
N.H. Rafai ◽  
Erween Abdul Rahim
Keyword(s):  
Thermal Conductivity ◽  
Stainless Steel ◽  
Titanium Alloy ◽  
Thermal Properties ◽  
Material Properties ◽  
Dissimilar Materials ◽  
Scanning Speed ◽  
Welding Parameters ◽  
Melting Region ◽  
Offset Distance

Welding parameters are directly influenced by the work material properties. Thermal properties such as thermal conductivity and melting point are very important to estimate the range of power required and the allowable scanning speed. However, when two or more different materials are involved, modifying lasing parameters are not enough to counter the problems such as imbalance melting region and weak adhesion of contact surface. To counter this problem, the characteristics of welding beads formation for both materials need to be clarified. In this study, comparison of welding beads constructed using the same scanning parameters were done to understand the different and similarity of melted region for the both materials. Actual welding of the both materials were done under different offset distance to obtain a balanced melting area and well mixed melting region.

scholarly journals Effect of Fiber Geometry and Representative Volume Element on Elastic and Thermal Properties of Unidirectional Fiber-Reinforced Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Siva Bhaskara Rao Devireddy ◽  
Sandhyarani Biswas
Keyword(s):  
Thermal Conductivity ◽  
Finite Element ◽  
Thermal Properties ◽  
Elastic Modulus ◽  
Cross Section ◽  
Representative Volume Element ◽  
Material Properties ◽  
Volume Element ◽  
Unidirectional Fiber ◽  
Representative Volume

The aim of present work is focused on the evaluation of elastic and thermal properties of unidirectional fiber-reinforced polymer composites with different volume fractions of fiber up to 0.7 using micromechanical approach. Two ways for calculating the material properties, that is, analytical and numerical approaches, were presented. In numerical approach, finite element analysis was used to evaluate the elastic modulus and thermal conductivity of composite from the constituent material properties. The finite element model based on three-dimensional micromechanical representative volume element (RVE) with a square and hexagonal packing geometry was implemented by using finite element code ANSYS. Circular cross section of fiber and square cross section of fiber were considered to develop RVE. The periodic boundary conditions are applied to the RVE to calculate elastic modulus of composite. The steady state heat transfer simulations were performed in thermal analysis to calculate thermal conductivity of composite. In analytical approach, the elastic modulus is calculated by rule of mixture, Halpin-Tsai model, and periodic microstructure. Thermal conductivity is calculated analytically by using rule of mixture, the Chawla model, and the Hashin model. The material properties obtained using finite element techniques were compared with different analytical methods and good agreement was achieved. The results are affected by a number of parameters such as volume fraction of the fibers, geometry of fiber, and RVE.

A Phase-Sensitive Technique for Measurements of Liquid Thermal Conductivity

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Zhefu Wang ◽  
Richard B. Peterson
Keyword(s):  
Thermal Conductivity ◽  
Stainless Steel ◽  
Thermal Properties ◽  
Steel Strip ◽  
Infrared Detector ◽  
Temperature Response ◽  
Front Surface ◽  
Test Liquid ◽  
Conduction Model ◽  
Conductivity Enhancement

An experimental technique based on the thermal wave approach for measuring the thermal conductivity of liquids is developed in this paper. A stainless steel strip functions as both a heating element and a sealing cover for a chamber containing a test liquid. A periodic current passing through this metal strip generates a periodic Joule heating source. An infrared detector measures the temperature response at the front surface of the stainless steel strip. The phase and magnitude of the temperature response with respect to the heating signal were measured by a lock-in amplifier at various frequencies from 22 Hz to 502 Hz. A one-dimensional, two-layered transient heat conduction model was developed to predict the temperature response on the front surface of the stainless steel strip. The phase information from this temperature response shows high sensitivity to the change in thermal properties of the liquid layer and is employed to match experimental data to find the thermal properties of the test liquid. The measured thermal conductivities of water and ethylene glycol agree quite well with the data from literature and support the validity of this measurement technique. An aqueous fluid consisting of gold nanoparticles is tested and anomalous thermal conductivity enhancement is observed. A discrepancy in the thermal transport behavior between pure liquids and nanofluids is suggested from our experimental results.

Laser Micro Welding of Dissimilar Material of Aluminum and Copper Alloys

2017 ◽  
Vol 882 ◽  
pp. 18-22
Author(s):  
Zazuli Mohid ◽  
M.A.A. Rosely ◽  
N.H. Rafai ◽  
Mohammad Zulafif Rahim ◽  
Mohd Rasidi Ibrahim ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Material Properties ◽  
Copper Alloys ◽  
Welding Process ◽  
Processing Parameters ◽  
Material Behavior ◽  
Fundamental Study ◽  
Melted Zone ◽  
New Material

Copper and aluminum are widely used in electronic industries for their excellence in electric and thermal conductivity. Joining these different material in scale of micro is hardly difficult for their obvious different in thermal properties. Melting these materials during welding process will create intermetallic compound which possesses new material properties. The melted zone became extremely brittle thus increase the possibility of failure due to cracks and concentrated loads. To overcome this problem, fundamental study is needed to characterize the material behavior against heat induction under various processing parameters. This study is an attempt to characterize the performance of Nd-YAG laser in micro joining of Al 1100 and Cu 101.

Thermal Vibrations of Beams With Temperature-Dependent Material Properties

1995 ◽  
Author(s):  
Abulkhair M. Masoom
Keyword(s):  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Stainless Steel ◽  
Elastic Modulus ◽  
Temperature Dependence ◽  
Material Properties ◽  
Temperature Dependent ◽  
Thin Beams ◽  
Thermal Vibrations ◽  
Coupled Theory

Abstract Thin beams subjected to thermal loads are considered. The formulation includes the temperature dependence of thermal conductivity and elastic modulus as well as coupled theory. A comparison is made between beams made of stainless steel and silicon carbide. Results show that significant differences are possible for temperature and stress solutions when temperature-dependent elasticity and conductivity are used, as opposed to the constant properties evaluated at a reference temperature.

scholarly journals Investigation of the Solid-Phase Joint of VT-14 Titanium Alloy with 12KH18N10T Stainless Steel Obtained by Diffusion Welding through Intermediate Layers

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1325
Author(s):  
Alexander Viktorovich Lavrishchev ◽  
Sergei Viktorovich Prokopev ◽  
Vadim Sergeevich Tynchenko ◽  
Aleksander Vladimirovich Myrugin ◽  
Vladislav Viktorovich Kukartsev ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Titanium Alloy ◽  
High Pressures ◽  
Solid Phase ◽  
Dissimilar Materials ◽  
Mechanical Tests ◽  
Diffusion Welding ◽  
Welding Temperature ◽  
Intermediate Layers ◽  
Welding Pressure

This paper describes the technological process of manufacturing bimetallic billets, which are capable of operating at high pressures, high temperatures, and in corrosive environments, from VT-14 titanium alloy and 12KH18N10T stainless steel. To obtain a joint with a strength of at least 350 MPa, the diffusion welding method was used, which makes it possible to obtain equal-strength joints using dissimilar materials. The connection of VT-14 titanium alloy with 12KH18N10T stainless steel after obtaining bimetallic billets with the desired properties was investigated. We studied the welded VT-14 and 12KH18N10T joint obtained by diffusion welding through intermediate spacers of niobium Nb (NbStrip-1) and copper Cu (M1). On the basis of our investigations, the optimum welding modes are as follows: welding temperature: 1137 K; welding pressure: 18 MPa; welding time: 1200 s. Mechanical tests, tightness tests, and metallographic, factographic, and micro-X-ray structural studies were carried out, the results of which indicate the effectiveness of the proposed approach.

Characterization of Material Properties for Multi-Scale Polymer Composites Extruded From Straight and Divergent Die Geometries Using Various Filler Concentrations

2015 ◽  
Author(s):  
Jason R. Nixon ◽  
Inna Lempert ◽  
Hyunjo Choi ◽  
Jeremy McFarlane ◽  
David I. Bigio
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Polymer Composites ◽  
Polymer Matrix ◽  
Material Properties ◽  
Transverse Direction ◽  
Polybutylene Terephthalate ◽  
Preliminary Results ◽  
Carbon Microfibers ◽  
Slit Die

The addition of nano-scale and micro-scale fillers has been proven to increase tensile and thermal properties in polymer composites. Orientation of high aspect fillers, however, has not been studied before despite being crucial to altering physical properties. When fibers are included during extrusion, they tend to align in the direction of the flow. This phenomena leads to longitudinal improvements in mechanical properties, and thus provides great benefits in some applications; however, it is beneficial to have improved properties in the transverse direction as well. Therefore, it is crucial to study reorientation phenomena in composites. The purpose of this experiment is to study property enhancement resulting from fiber structure. The material properties are compared for the range of weight percentages of fillers. This is done for the purpose of finding an ideal fill concentration. Two dies are used to study different orientation distributions: straight and divergent. Thermal and tensile properties and optical micrographs are analyzed and compared. Composites were processed on a Coperion ZDSK-28mm co-rotating, fully-intermeshing, twin-screw extruder. Polybutylene terephthalate (PBT) was used as the polymer matrix. 0 W% to 2 W% multi-walled carbon nanotubes (CNTs) and 0 W% to 30 W% carbon microfibers (CMFs) were used as fillers. Preliminary results showed a clear trend in increased tensile strength of the composite with the increase of concentration of CMFs and CNTs in the slit die up to 25 W% CMF. After 25 W% CMF, however, there was a depreciation in properties. Similarly, thermal conductivity results have shown a clear peak at 25 W% CMF with 30 W% showing a decrease in thermal properties. Preliminary results for the divergent die showed that, with addition of carbon microfibers to the polymer matrix, thermal properties of the composite increased up to 15 W%, then dropped and increased again as more CMFs were added. In addition, on average, material extruded through the divergent die showed better results of thermal conductivity than that extruded through the slit die. This indicates that when using a diverging die, fiber become oriented perpendicular in relation to the direction of the flow, thus improving heat flow in the transverse direction.

Thermal Wave Based Measurement of Liquid Thermal Conductivities

2008 ◽  
Author(s):  
Zhefu Wang ◽  
Richard B. Peterson
Keyword(s):  
Thermal Conductivity ◽  
Stainless Steel ◽  
Thermal Properties ◽  
Steel Strip ◽  
Measurement Techniques ◽  
Temperature Response ◽  
Front Surface ◽  
Conduction Model ◽  
Closed Chamber ◽  
Thermal Conductivities

This work develops an experimental technique capable of determining thermal conductivity of liquids with application to nanofluids. A periodic current passing through a thin stainless steel strip generates a periodic Joule heating source and an infrared detector measures the temperature response at the front surface of the stainless steel strip. An open chamber is machined out of a delrin plate with the stainless steel strip acting as the sealing cover. This resulting closed chamber contains the test liquid. The phase and magnitude of the temperature response were measured using a lock-in amplifier at various frequencies from 22 to 502 Hz. A one-dimensional, two-layered transient heat conduction model was developed to predict the temperature response on the front surface of the stainless steel strip. This temperature response, including phase and magnitude, is a function of the thermal properties of the liquid. The phase information shows high sensitivity to thermal properties of the liquid layer and is employed to match experimental data to find thermal conductivities. The measured thermal conductivities of water and ethylene glycol agree well with data from the literature and support the validity of this measurement technique. An aqueous fluid consisting of gold nanoparticles was tested. Anomalous thermal conductivity enhancement was observed. Our measurement results also show a divergence of thermal transport behavior between nanofluids and pure liquids. This suggests the need to carefully examine the role of measurement techniques in the study of nanofluid heat transfer phenomena.

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