Small hole fabrication through additively manufactured CuCr1Zr electrode during EDM of a novel Haynes 25 superalloy

Present work proposes an extensive experimental investigation to evaluate the machinability of Haynes 25 work piece with additively manufactured CuCr1Zr (prepared through selective laser melting process), pure copper and graphite electrodes, in view of producing small holes of diameter 3 mm. Prior to machinability investigation, material characterization studies in terms of energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) analysis along with several other mechanical as well as physical properties such as density, microhardness, tensile strength, electric conductivity and thermal conductivity, are carried out for both the electrodes. Outcomes of critical process parameters viz. current (I), voltage (V), pulse on time (Ton), duty factor (τ), and flushing pressure (Fp) are studied on performance measures such as material removal rate (MRR), electrode wear ratio (EWR), specific energy consumption (SEC), surface roughness (Ra), and radial overcut (ROC). The EDMed surface is carefully analysed by a field emission scanning electron microscopy (FESEM) study. It is observed that additively manufactured CuCr1Zr electrode is proficient enough to produce parts with greater accuracy, improved surface finish with least amount specific energy consumption, thus saving cost and time during machining. The ideal level of cutting parameters are identified, validated with confirmative experiment with an average error of 2.79 percentages to produce precise accurate EDMed parts. This work delivers an energy efficient as well as cost effective machining strategy to produce precise and accurate small holes for EDMed applications, thus paving way for productivity of the process

Acute naphthalene toxicity presenting with metabolic acidosis: a rare complication

Naphthalene moth ball poisoning in children can present with diagnostic and therapeutic challenges. A 2 year old boy who had accidentally consumed unknown number of moth balls presented 3 d later with vomiting, seizures, methemoglobinemia, hemolytic anemia and altered sensorium. He was managed with red blood cell transfusion, IV Methylene blue and Sodium bicarbonate. Clinical and laboratory parameters normalized. We describe this case as ingestional naphthalene poisoning with rare manifestation of metabolic acidosis, with a good outcome after treatment

Reviewing Performance Measures of the Die-Sinking Electrical Discharge Machining Process: Challenges and Future Scopes

The most well-known and widely used non-traditional manufacturing method is electrical discharge machining (EDM). It is well-known for its ability to cut rigid materials and high-temperature alloys that are difficult to machine with traditional methods. The significant challenges encountered in EDM are high tool wear rate, low material removal rate, and high surface roughness caused by the continuous electric spark generated between the tool and the workpiece. Researchers have reported using a variety of approaches to overcome this challenge, such as combining the die-sinking EDM process with cryogenic treatment, cryogenic cooling, powder-mixed processing, ultrasonic assistance, and other methods. This paper examines the results of these association techniques on various performance measures, such as material removal rate (MRR), tool wear rate (TWR), surface roughness, surface integrity, and recast layer formed during machining, and identifies potential gap areas and proposes a solution. The manuscript is useful for improving performance and introducing new resolutions to the field of EDM machining

Case Report Primary Amoebic Meningoencephalitis in an Infant due to Naegleria fowleri

Primary amoebic meningoencephalitis (PAM) caused by free-living amebae Naegleria fowleri is a rare and fatal condition. A fatal case of primary amoebic meningoencephalitis was diagnosed in a 5-month-old infant who presented with the history of decrease breast feeding, fever, vomiting, and abnormal body movements. Trophozoites of Naegleria fowleri were detected in the direct microscopic examination of CSF and infant was put on amphotericin B and ceftazidime. Patient condition deteriorated, and he was discharged against medical advice and subsequently expired. We also reviewed previously reported 8 Indian cases of primary amoebic meningoencephalitis (PAM) and observed that for the last 5 years, none of the patients responded to amphotericin B. Has an era of amphotericin B-resistant Naegleria fowleri been emerged? Management strategy of PAM needs to be reviewed further