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Machining Investigations of Squeeze Cast TiB2/Al 7075 Composites through EDM: Regression Modelling and Weighted Principal Component Analysis

Pradhan Rahul Chandra, Das Diptikanta, Sahoo Barada Prasanna, Rout Chiranjeeb, Panda Akash, Barla Evangelin

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

551--562

EN

2 wt.% TiB2 (mean particle size: 400 nm) reinforced Al 7075 metal matrix composites (MMCs) fabricated through mechanical stirring and ultrasonic agitation integrated squeeze casting process were subjected to electrical discharge machining (EDM) after determining the physical and mechanical properties. EDM was conducted with Cu electrode tools to investigate influence of machining factors, i.e. peak current (IP), pulse on time (TON) and gap voltage (VG) on the tool wear rate (TWR), material removal rate (MRR) and average surface roughness (ASR) of the machined surfaces. All the three responses increased on increasing IP and TON, but reduced on increasing VG. The machined surfaces were studied through scanning electron microscope (SEM). Significance of the EDM parameters on the individual responses were studied using analysis of variance (ANOVA) and regression models for the responses were developed using response surface method (RSM). The responses under consideration were optimized simultaneously using Taguchi embedded weighted principal component analysis (WPCA), which resulted the parametric combination of 4A (current), 100 μs (pulse duration) and 75V (voltage) was the optimal setting for the multi-criteria decision problem. Finally, the result of optimization was validated by conducting some confirmatory experiments.

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Tribological Properties of Al 7075 Composite Reinforced with ZrB2 Using Grey Relational Analysis

Karumuri Srikanth, Das Vemulapalli Chittaranjan, Gopi Krishna Mallarapu

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 4

22--28

EN

In this work, the authors investigate the optimal tribological parameters of Al 7075 composite reinforced with ZrB2 using Grey Relational Analysis (GRA). Initially, the composite specimens were prepared by the variation of reinforcement 5%, 10% and 15% using stir casting routing method. Further, the developed metal matrix composites are used to measure the wear and frictional properties on pin-on – disc testing apparatus. The input parameters such as, wt% of reinforcement (5%, 10% and 15%), load (4.92N, 9.81N and 14.72N) and the time required for conducting the wear test is (15 min. 30 min and 45 min). A Taguchi L9 orthogonal array was designed for conducting the number of experiments. Based on the combination of number of experiments wear study has been conducted on the wear testing apparatus. Moreover, GRA was used for obtaining the best optimal input control parameters that gives minimum magnitude of wear and coefficient of friction (COF). Finally, the confirmatory experiments are conducted and verified with the Taguchi grey relational analysis. The results shows that the predicated optimal mean value is almost similar to the experimental value.

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Effects of B addition on the microstructure and microhardness of melt-spun Al-7075 alloy

Kilicaslan Muhammed Fatih, Elburni Saad Ibrahim, Yilmaz Yasin, Akkaş Mehmet

Advances in Materials Science

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2022

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Vol. 22, nr 2(72)

5--18

EN

Main aim of this study is to examine change of microstructural and the mechanical properties of Al-7075 alloy depending on B content added with different proportions. Rapid solidification process used to produce the alloys was carried out with a single roll melt spinner via a wheel with a rotational speed of 25 m/s. For the microstructural characterization of the alloys, a scanning electron microscope and X-ray diffraction analyzes were used. According to obtained results, it can be said that B addition led to modification of dimensions and shapes of both α−Al and intermetallic phases occurred, it reduced average grain size from 0.45 μm to 0.34 μm in the microstructure. The B addition also led to dramatically increase in microhardness of the Al-7075 alloy. The microhardness of the alloy with 0.4 wt. % B is 0.19 GPa, this is clearly one times higher than that of the alloy without B addition. The microhardness of the alloy with 1 wt. % B is 0.21 GPa, this is also slightly higher than that of the alloy with 0.4 wt. % B.

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Investigation of Mechanical and Corrosion Properties of Al 7075/Garnet Metal Matrix Composites by Two-stage Stir Casting Process

Sambathkumar Mani, Navaneethakrishnan P., Sasikumar K. S. K., Gukendran Rangasamy, Ponappa K.

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 4

1123--1129

EN

The impact of Garnet addition into the AL7075 aluminium matrix on the physical, mechanical and corrosion properties are studied in this research paper. Al 7075/garnet composites are fabricated by using two-stage stir casting method in different (0, 5, 10, 15) volume percentages. Photomicrograph of prepared samples revealed the uniform distribution of garnet reinforcement into the base matrix. The corrosion rate is calculated by potentiodynamic polarization method. The actual density is increased by around 1.2% for al 7075 / garnet (15%) composite as compared to base alloy. Micro hardness of al 7075 / garnet (15%) composite is raised by around 47 (34%) compare to as cast base matrix. Al 7075 / garnet (15%) composite tensile strength stood at 252 Mpa, which is 40% greater than the base alloy. Al 7075 / 15% garnet composites reduce around 97% of corrosion rate than the base matrix. Alloy elements influenced the corrosion than Garnet reinforcement.

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Effect of tool eccentricity on microstructure and properties of fsw joints made of Al 7075 T6 alloy

Burek R., Wydrzyński D., Andres J., Wrońska A.

Advances in Science and Technology. Research Journal

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2017

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Vol. 11, no 4

333--338

EN

The aim of this paper was to present preliminary results of researches conducted in PZL Mielec within the FAST_FSW project (INNOLOT program) on the influence of tool eccentricity on microstructure and mechanical properties of 1.6 mm and 0.8 mm thick Al 7075 T6 sheets joints. Samples were performed using CNC milling machine. The range of tool eccentricity was 0–0.3 mm, rotational speed and feed rate were variable. The influence of the applied welding parameters on microstructure and mechanical properties of joints was assessed on the basis of metallographic inspections and tensile tests. Microstructural observations have shown that the change of FSW tool eccentricity affects the weld geometry: the mixing zone depth, the weld width, or the shape of the contact line.