Linear friction welding of a near-β titanium alloy

The linear friction welding (LFW) behaviour of near-β titanium alloy Ti-5Al-5V-5Mo-3Cr (Ti-5553) was investigated by varying the processing conditions of frequency and axial pressure. The examined mechanical properties of the welded material included microhardness and tensile properties. The maximum strains experienced by the material during LFW for each set of welding parameters were estimated based on the process parameters and then evaluated using Aramis, a three-dimensional optical deformation measurement system. The LFWed Ti-5553 was examined with electron backscatter diffraction techniques to relate the texture and phase changes to the thermomechanical conditions. Characterisation of the welds included analysis of the microstructural features of the weld region and the thermomechanically affected zone in relation to the parent material.     

Substrate Integrated Waveguide Corrugated Horn Antenna

Wireless Personal Communications - In this paper, a substrate integrated waveguide (SIW) H-plane horn antenna is proposed. We first optimize the antenna in size to obtain the maximum gain. The SIW...     

Electricity price forecasting using neural networks with an improved iterative training algorithm

In a competitive electricity market, the forecasting of energy prices is an important activity for all market participants either for developing bidding strategies or for making investment decisions. In this article, a new forecasting strategy is proposed for short-term prediction of the electricity price, which is a complex quantity with nonlinear, volatile and time-dependent behaviour. Our forecast strategy includes two novelties: a new two-stage feature selection algorithm and a new iterative training algorithm. The feature selection algorithm has two filtering stages to remove irrelevant and redundant candidate inputs, respectively. This algorithm is based on mutual information and correlation analysis. The improved iterative training algorithm is composed of two neural networks in which the output of the first neural network is one of the inputs to the second. The overall proposed strategy is applied to the Pennsylvania–New Jersey–Maryland (PJM) electricity markets and compared with some of the most recent price forecast methods.     

Influence of deformation path change on static strain aging of cold rolled steel strip

Effect of deformation path change on the static strain aging of low carbon steel was studied in this work. In the first stage, strip samples were subjected to cold rolling processes under different paths with the same total reduction in thickness while the deformation behaviors of the rolled samples were also evaluated using a mathematical analysis. Then, cold-rolled strips were aged in room temperature up to 45?days while hardness and tensile evaluations were performed to assess the mechanical properties of the as-rolled and the aged samples. Finally, the influence of rolling pass schedule on the subsequent strain aging phenomenon was investigated by means of the experimental results and the predictions. The results indicate that rolling path schedule significantly changes plastic strain and residual stress distributions. Furthermore, the kinetics of aging phenomenon also varies after different rolling paths where a schedule containing two-pass reverse layout may result in the fastest aging kinetics.     

Linear Friction Welding of Dissimilar Materials 316L Stainless Steel to Zircaloy-4

Metallurgical and Materials Transactions A - In the nuclear industry, there are a number of applications where the transition of stainless steel to Zircaloy is of technological importance. However,...