NOPR Collection:

Optimization of the surface roughness and material removal rate in turning of unidirectional glass fiber reinforced plastics using the fuzzy-grey relational technique

Fri, 01 Feb 2019 00:00:00 GMT

Title: Optimization of the surface roughness and material removal rate in turning of unidirectional glass fiber reinforced plastics using the fuzzy-grey relational technique Authors: Kumar, Surinder; Meenu Abstract: In this paper fuzzy-grey relation technique is applied to experimental results in order to optimize the turning of unidirectional glass fiber reinforced plastics composite with consideration to multiple performance measures. The overall grey relational grade is found using fuzzy logic. To conduct experimentation L₁₈ orthogonal array of Taguchi is used. Cutting speed, depth of cut, feed rate, tool rake angle, tool nose radius and environment (dry, wet, cool) are taken as parameters for experimentation. Castrol water miscible soluble coolant (1:6) volumetric concentrations is used as cutting fluid. A1B1C1D1E3F1 is found to be the optimal setting for optimizing material removal rate and surface roughness. Depth of cut followed by cutting speed is found to be most influential factor by the average of grey relational grade analysis using Fuzzy logic. Page(s): 7-19

Friction-wear behavior of shot peened aluminium 7075-T651 alloy

Fri, 01 Feb 2019 00:00:00 GMT

Title: Friction-wear behavior of shot peened aluminium 7075-T651 alloy Authors: Abeens, M; Muruganatham, R; Arulvel, S Abstract: The present study reports the friction-wear behavior of un-peened and shot peened aluminium 7075-T651 alloy against aluminium 7075-T651 alloy in dry sliding condition. Shot peening was done using CI steel ball (40-45 HRC) with 0.6 mm diameter. Phase Structure, hardness, compressive residual stress, surface morphology and surface features are characterized using X-ray diffractometer (XRD), Vickers hardness tester, noncontact-surface profile meter and scanning electron microscope (SEM). Sliding wear test were conducted against aluminium 7075-T651 alloy in dry sliding condition at room temperature using a pin on disc apparatus. A 25% increase in the hardness was seen for shot peened aluminium 7075-T651 alloy. Shot peened aluminium 7075-T651 alloy has induced maximum compressive residual stress of -188 MPa. No new phases were formed for the shot peened aluminium 7075-T651 alloy, however, the shift in the plane is observed. There was also a drastically increase in surface roughness in spite of the peening process. Adhesive wear was the dominant wear mechanism for the un-peened specimen, whereas, it was reduced for the shot peened surfaces. Page(s): 20-26

Effects of process parameters on mechanical and metallurgical properties in high pressure die casting of AZ91 magnesium alloy

Fri, 01 Feb 2019 00:00:00 GMT

Title: Effects of process parameters on mechanical and metallurgical properties in high pressure die casting of AZ91 magnesium alloy Authors: Vanli, Ali Serdar; Akdogan, Anil Abstract: High pressure die casting (HPDC) of magnesium (Mg) alloys has been the fastest grown up and the most globally developed section in magnesium industry. HPDC of complex shape Mg alloy products have increased considerably in recent years. But low mechanical and metallurgical performance of the casting products could be experienced due to defects in HPDC of Mg alloy parts under heavy working conditions. Process technologies should be modified and process parameters need to be optimized for the use of Mg based alloy products as high performance casting parts. The correct selection of the process parameters means the correct manufacturing of the casting parts. There is a wide range of suggested process parameters for HPDC of different Mg alloys in the literature. This paper specifies optimum process parameters for the required mechanical and metallurgical properties of the die casting parts, experimentally. Experimental tests are performed by using Taguchi experimental procedure to determine the optimum process parameters in cold chamber HPDC of Mg alloy parts. Confirmation and statistical analyzing tests have confirmed the results. The results minimize the available range of process parameters in the literature for high mechanical properties and low porosity content of casting products by conducting the designed experiments in an industrial scale mass production line considering the product quality. Page(s): 27-35

Magnetic and dielectric properties of Ca2+ doped Bi0.9La0.1FeO3 nanoparticles prepared by the sol-gel method

Fri, 01 Feb 2019 00:00:00 GMT

Title: Magnetic and dielectric properties of Ca2+ doped Bi0.9La0.1FeO3 nanoparticles prepared by the sol-gel method Authors: Yang, Fang; Li, Mei; Yang, Hu; Lin, Jinpei; Huang, Kangling; He, Yun; Lin, Qing Abstract: Bi_0.9-xLa_0.1Ca_xFeO₃(x=0.05~0.25) nanoparticles were synthesized by an improved sol-gel technique. With an increasing x value, the grain size exhibits an initial drop followed by a subsequent rise. The temperature has a strong effect on the morphology of samples. This implies that 700℃ is the optimal temperature for the growth of crystals in the samples. The magnetization increases with an increase in the concentration of Ca²⁺ions, and the doped crystals exhibit important features of anti-ferromagnetic spin ordering. The remanent magnetization (M_r) exhibits an initial reduction with a subsequent increase versus concentration (x) of Ca²⁺ ions, its minimal value corresponding to x=0.2. The substitution of Bi³⁺ions by Ca²⁺ ions results in the change of the Fe³⁺-O-Fe³⁺bond angle, accompanied by a distortion of the oxygen octahedra. With an increase in frequency, multiple Debye peaks appear in all samples, which indicate that the material possesses multiple-frequency energy absorption characteristics. Thus, the frequency-dielectric loss curve is characterized by the superposition of multiple Debye peaks. Page(s): 36-42