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Increasing the etching rate is one of the main optimization targets in the Chemical Machining (CM). Traditionally, this target is fulfilled by some costly techniques like selecting stronger etchants and increasing the etchant concentration. Also, other methods like increasing the etchant temperature and stirring the etchants by agitators are employed for increasing the etching rate. One of the advantages of these methods is reduction of the consumption of acidic etchants which results in the cost reduction and making an eco-friendley process. In this article, a systematic experimental study is performed on vibration-assisted CM of copper. In this technique, the workpiece vibrates in the etchant during the CM. For evaluating the performance of machining, effects of amplitude and frequency of vibrations, along with the temperature and concentration of acidic etchant, on material removal rate, surface roughness and machining undercut are studied experimentally. The experiments are designed by Central Composite Design (CCD) in Response Surface Methodology (RSM). Also, multi-objective optimization is performed by defining a desirability function. The optimal vibro-assisted process parameters are temperature 60°C, etchant concentration 600 g/l, vibration frequency 25 Hz, and vibration amplitude 1.5 mm, to get optimal outputs on the desired parameters. [ABSTRACT FROM AUTHOR]

Chemical etching is a crucial process in materials science that involves controlling material removal through chemical reactions. It offers precise surface manipulation for various applications. In this study, the focus was on investigating the influence of temperature and etching solution concentration on the corrosion rate and surface roughness of aluminum alloy 2024. A range of temperatures (from 35 to 65°C) was selected with increments of 5 °C. Three concentrations (9, 20 and 29 Be) of the etching solution (ferric chloride) were examined. The experimental results revealed that both the corrosion rate and surface roughness increased with higher temperatures and concentrations. The values of corrosion rate and surface roughness varied from 1.15 x 10-4 mm/min and 1.208 μm, respectively at 35 °C, to 1.291 x 10-3 mm/min and 7.431 μm, respectively at 65 °C. However, the effect of temperature was found to be more significant than that of concentration for the range under study. Understanding the relationship between temperature, concentration, corrosion rate, and surface roughness in chemical etching of Al-2024 enables the optimization of the process for tailored material properties. This can be helpful in industrial application fields that require precise surface manipulation, such as automotive, airplanes, aerospace, medical, households and consumer electronics. [ABSTRACT FROM AUTHOR]

Due to the high demand for innovative parts from the aerospace, biomedical, and automotive industries, 3D printing of titanium parts is widely researched. Electron beam melting (EBM) is one of the few additive manufacturing techniques that can quickly generate high density components. However, additive manufacturing techniques based on powder beds are characterized by subpar surface finishing, which also results in poor mechanical performances that are not suitable for industrial standards. Thus, surface finishing post processing is generally needed. Since fatigue behavior is strongly affected by surface quality, this work aims to highlight how chemical machining impacts this type of mechanical response. Rotating fatigue beam testing method has been chosen for the experimental campaign since it intrinsically stresses more the sample surfaces, in this way the effect of surface finishing is highlighted. [ABSTRACT FROM AUTHOR]

Chemical Machining (CHM) is a non-conventional machining process, which is used to machine hard brittle materials. The objective of this paper is a literature survey related to the chemical machining process. In this machining process, the chemical energy of the etchant is used to remove the excess materials from the workpiece; materials will be removed through the chemical dissolution process. In the literature, it is identified that so many factors influence the process of chemical machining such as concentrate of etchant, the temperature of the etchant, masking methods, types of the masking and etchants. It is also identified that these process parameters influence the material removal rate (MRR) and surface finish.

Abstract Recent achievements made in the field of ceramics and glass technology demands the development of hybrid techniques to process those advanced materials precisely and efficiently. Chemo-thermal micromachining is a novel method of micro-fabrication, achieved by integrating laser based thermal ablation and chemical etching. This hybrid process involves focusing laser beam on a borosilicate glass specimen submerged in aqueous sodium hydroxide solution that causes chemical machining along with thermal ablation at the focused point. In this study, an attempt has been made to explore the effects of machining parameters like laser power, laser exposure duration and electrolyte concentration on material removal rate (MRR) and surface quality that involves study of surface cracks and built-up edges along the machined surface of borosilicate glass. A four-level full factorial experimental design was adopted to understand the effect of each parameter. Additional experiments have been conducted to identify the effect of laser and chemical machining separately. It was found that there was a reduction of about 90% in the average length of crack in chemo-thermal micromachining process as compared to laser ablation alone. Also, the number of cracks was reduced from about 20-23 in laser machining to 1–5 in this hybrid machining. Highlights • A hybrid micromachining process combining thermal ablation with chemical machining is proposed. • Effects of process parameters on surface quality and material removal rate in glass are studied. • This hybrid process significantly reduces surface cracks and built-up edges in the micro drilling of glass. [ABSTRACT FROM AUTHOR]

Chemical machining is one of the oldest nontraditional machining processes. It applies chemical etchant to machine material. The method is very basic and economical to produce complex geometrical parts from thin sheet materials. The application of this method to cylindrical parts is not common. In this study, chemical machining process was employed to machine rod as cylindrical part. The selected material was St37 with diameter of 10 mm. The experimental study implemented ferric chloride, which is known a universal chemical etchant for ironbased materials, at three different etchant solutions in two chemical machining temperatures (30 °C and 50 °C). The experimental setup is based on upright drilling machine that has three different spindle speed values (250, 500, and 1500 rpm). It was observed that lower etchant concentration provided higher diameter reduction, surface roughness, and cylindricity. Moreover, the effect of chemical machining temperature is examined and increase of this value produced faster machining. [ABSTRACT FROM AUTHOR]

Chemical machining is one of the oldest nontraditional machining processes. It applies chemical etchant to machine material. The method is very basic and economical to produce complex geometrical parts from thin sheet materials. The application of this method to cylindrical parts is not common. In this study, chemical machining process was employed to machine rod as cylindrical part. The selected material was St37 with diameter of 10 mm. The experimental study implemented ferric chloride, which is known a universal chemical etchant for ironbased materials, at three different etchant solutions in two chemical machining temperatures (30 °C and 50 °C). The experimental setup is based on upright drilling machine that has three different spindle speed values (250, 500, and 1500 rpm). It was observed that lower etchant concentration provided higher diameter reduction, surface roughness, and cylindricity. Moreover, the effect of chemical machining temperature is examined and increase of this value produced faster machining. [ABSTRACT FROM AUTHOR]

Grinding-assisted chemical etching (GACE) is hybrid machining process, which combines the chemical and mechanical (grinding) machining. The features of this process are the ability to grinding nonferrous metals and improved surface finishing in comparison with typical grinding. In this study, attempts to grinding Al-EN AW-7075 with FeCl etchant and the integrity of the machined surface have been discussed. It was observed that by applying the GACE operation in grinding of aluminum, surface roughness decreased. Comparative observations are made, in order to show the potential of the present process modifications to improve the productivity during grinding Al-EN AW-7075 in relation to the conventional methods. [ABSTRACT FROM AUTHOR]

The necessity to have components with fine surfaces has prompted many scholars to study the methods for finishing the surface of specimens. Recently, the investigations are more focused on the elimination of recast layer, surface layer engendered by wire electrical discharge machining (WEDM) process which diminishes the properties of components. In this work, a new setup involved of ultrasonic waves, etching acid and abrasive particles was developed. Then the capability of this new innovative recast layer removal mechanism was tested by design of experiments method. Three-level full factorial technique was used to study the effective parameters on recast layer removal. The analysis of variance has been used to indicate the significant factors. Based on the regression model, a mathematical relationship between the input factors and the output of material removal was obtained. Experimental results proved that etch assisted ultrasonic floating abrasion process removed the recast layer completely and left a surface free of microcracks. In addition, the parameters of machining time and acid concentration were found to be the most significant factors on the output of the material removal and recast layer thickness. [ABSTRACT FROM AUTHOR]

Abstract: Chemical machining of nanocrystalline Ni has been studied for the first time. Mass loss as a function of machining time in aqueous FeCl3 solutions was measured. Machining rates in nanocrystalline Ni were approximately an order of magnitude higher than conventional polycrystalline Ni for the same FeCl3 concentrations. While the system obeys first-order reaction kinetics, there were significant differences in the surface morphology depending on the FeCl3 concentration. Scanning electron microscopy of samples machined at low concentration showed deep pitting, while those machined at higher concentrations exhibited the desired uniform mass loss. Present results show that room temperature machining operations can be successfully applied to nanocrystalline Ni. [Copyright &y& Elsevier]

Abstract: Commercial open-cell aluminum alloy foams are subjected to chemical dissolution to reduce their density. Dissolution rates are measured for various pH, temperature and alloy heat-treatment conditions, and the resulting foam structures and surface conditions are evaluated by microscopy and X-ray microcomputed tomography to identify conditions which minimize corrosive damage. The effect of uniform dissolution on foam compressive mechanical properties is interpreted in terms of these observations. A method for production of density-graded foam samples from uniform-density precursors is also demonstrated. [Copyright &y& Elsevier]

The present work is an investigation aimed at reducing pitting problem and obtaining better surface finish in chemical machining of St304. A new etchant is introduced for chemical machining of St304. Results present good surface finish without any pitting while high machining rate is achieved. The etchant tested in several temperatures and different depths of machining and the results are compared with other etchants, which are introduced in some references [Chemical Milling Nontraditional Machining Process, Machining ASM Handbook, 1994; Chemical Machining, Metals Handbook, vol. 3, Machining, 8th ed., American Society for Metals, Metals Park, OH, pp. 240–248; Fontana, Mars, G., Corrosion Engineering, 30th ed., 1986]. New etchant is a mixture of H2O+HCl+HNO3+HF+H2COOH+TEA. Scan electron microscope (SEM) and roughness tests were employed to observe the surface topography. [Copyright &y& Elsevier]

Aluminium is one of the main engineering materials used extensively in aircraft and automotive industries where the weight is an important factor. Chemical machining of aluminium and its alloys has widely been studied to produce parts. Chemical machining is based on selection of optimum chemical solution which is named as etchant for shaping the required material. In this study, chemical machining of aluminium and its alloys has been surveyed to provide scientific data for industrial applications. Other chemical machining parameters such as etchant concentration, chemical machining temperature, and additives to main etchant have been extensively examined. [ABSTRACT FROM AUTHOR]