Journal of Modern Processes in Manufacturing and Production
Volume:9 Issue: 1, Winter 2020

In the laser cutting process some well-known parameters, e.g. laser power and cutting speed, play major roles in the performance of the process. Each parameter or a combination of parameters can affect the material removal volume and cutting volume efficiency. The purpose of this research is to study the effect of power and maximum cutting speed on the material removal rate (MRR) and cutting volume efficiency (αVol) in CO2 laser cutting of polycarbonate (PC) sheets. A CO2 laser cutting machine with a maximum power of 130 W was used to cut PC sheets with thicknesses of 2 to 8 mm. The spot size of the focused beam was 0.1 mm on the upper surface of the sheet. The cutting experiments were carried out by varying the laser power from 20 to 100 W and the maximum cutting speed was found for each power. In the range of applied laser parameters for cutting of PC sheets, the results show that the MRR increases with power. The results also indicate that the MRR increases with maximum cutting speed and thickness. The cutting volume efficiency (αVol) increases with power until it reaches the apex of efficiency then, it slightly reduces with increasing power.

Recent advances in technology have increased the necessity of using components with Micro and Nano dimensions. In recent years, the use of bacteria as a renewable tool has hopeful applications in producing different work-pieces. In this study, the effect of Acidithiobacillus Ferrooxidans (A.F) on Vt20 (Titanium alloy) and Cu were investigated. The results illustrated that in the medium of the Aerobic bacteria A.F, the layer of TiO2 on the surface of Vt20 is formed and this oxide layer impedes Vt20 corrosion. Furthermore, it was observed that Cu in a medium of A.F is corroded in the same condition. According to these results, biomachining by A.F is considered as a new approach that is used for Micro-Bio grooving on Cu, but this method has different effects on Vt20. So that due to improving the hardness of Vt20 and high resistance of this alloy against abrasion, this method can be used for coating space traveling equipment, automotive industries and home appliance. On the other hand the effect of pH and temperature on Vt20 were studied and it was observed that the increase in pH and temperature improve the resistance of Vt20 against the surface corrosion.

Titanium and its alloys (Ti-6Al-4V) are considered to be among the most promising engineering materials due to a unique combination of high strength to weight ratio, melting temperature, corrosion resistance, and biocompatibility. Anodizing is one of the coating methods that increases corrosion resistance and wear resistance and provides better adhesion of paint primers mostly applied to protect Al, Ti, Mg, and their alloys. The novel Plasma Electrolytic Oxidation (PEO) technique is gaining increased attention for depositing thick, dense, corrosion resistant, and hard ceramic coating on valuable metals (Al, Ti, and Mg). The aim of this research is a comparison between the corrosion behavior of anodized and plasma electrolytic oxidized Ti-6Al-4V at different voltages. The surface morphology, thickness, and phase composition of coatings were investigated using a scanning electron microscope and X-ray diffraction. The potentiodynamic polarization test was used to determine the corrosion behavior of the specimens. Results indicated that increasing of corrosion resistance by tests anodized sample at 50 V at 15 minutes and PEO sample at 375 V at 10 minutes.

Magnesium alloys are important materials in industries because of their low densities. But the problem with these alloys is their lack of creep resistance at high temperatures. In this research, the creep behavior of cast ZE63 and ZE41 magnesium alloys were studied by using the impression creep method. The tests of impression creep were carried out at a temperature of 473 Kelvin and constant punching stress range of 175MPa to 500MPa. Microstructural investigation of magnesium alloys was performed using an optical microscope and X-ray diffraction (XRD). The results of XRD analysis indicated that the structures of both alloys were composed of α-Mg matrix phase accompanied by Mg7Zn3, Mg12RE, and Mg17RE2 intermetallic compounds. Besides, the analysis of the microstructure of deformation zones showed that the creep resistance of ZE63 was higher than ZE41. The higher creep resistance of ZE63 was attributed to the existence of more continuous phases of Mg7Zn3, Mg12RE, and Mg17RE2.

The imperialist Competitive Algorithm (ICA) is one of the recent meta-heuristic algorithms proposed to solve optimization problems. The Imperialist Competitive Algorithm is based on a socio-politically inspired optimization strategy. This paper presents an Imperialist Competitive Algorithm (ICA) to optimize the performance of a surface grinding operation.  Moreover, the multi-objective optimization of a surface grinding process is suggested by using an evolutionary algorithm. Factors like depth of dressing, lead of dressing, workpiece speed and wheel speed are considered to minimize the production cost, surface roughness and to maximize the production rate. The suggested approach presents two constraints handling techniques: constraints handling strategy of ICA and penalty function method. The effectiveness of this algorithm for grinding operation is investigated by comparing the results to other algorithms available in the literature. Results show that the proposed algorithm in this work gives a better performance in a shorter time for the optimization of machining parameters in comparison to other works.

CK45 steel is a suitable material for the manufacturing of forging dies. This paper investigates the influence of electrical discharge machining (EDM) parameters including voltage, current, on-time and off-time on the microstructure of the machined surface of this material. The process induces thermal stresses that in turn result in the generation of widespread micro-cracks on the surface of the part subjected to spark EDM. The influence of EDM parameters on the quality of the machined surface is explored by performing an extensive experimental program. The impact of EDM parameters on the surface roughness and the intensity of micro-cracks have been evaluated quantitatively using the test results and regression analysis. Predicting the relationship between EMD parameters and the surface quality provides practical means to appropriately decide on the adjustment of process control parameters to their optimum values and hence to achieve the desired surface quality at reasonable manufacturing times and cost.