National Aerospace Laboratories

About: National Aerospace Laboratories is a facility organization based out in Bengaluru, India. It is known for research contribution in the topics: Coating & Corrosion. The organization has 1838 authors who have published 2349 publications receiving 36888 citations.

Mechanical micro-drilling of nimonic 80A superalloy using uncoated and TiAlN-coated micro-drills

Abstract: Micro-drilling is a complex mechanical machining process. Micro-drilling experiences an early tool damage which is a major drawback for nickel-based superalloy. This paper examines the wear condition on the micro-tool cutting edge, surface roughness of machined holes, and hole diameter analysis in micro-drilling of Nimonic 80A, using two types of micro-drills (uncoated and TiAlN coated) with 0.79 mm diameter. Micro-drilling tests, using cutting speed (Vc), feed rate (fz), and the micro-drill diameter as experimental parameters were carried out to bring out the best optimized machining conditions in micro-drilling of Nimonic 80A. Wear on the tool cutting edge and burr height occurring at the entrance of drilled holes were measured at constant period to give the lastingness of micro-drill. Quality of holes were analyzed in terms of surface roughness inside the hole and the hole diameter after every five drilled holes. The result obtained from the above analysis showed that TiAlN-coated micro-drill p...

Highly sensitive giant magnetoresistance (GMR) based ultra low differential pressure sensor

Abstract: In this study, we demonstrate a simple, cost-effective, giant magnetoresistance (GMR) based magnetic pressure sensor The basic principle lies behind the measurement of the change in the magnetic field profile generated by the deflected diaphragm attached with a permanent magnet This magnetic field profile change on the sensor surface was measured by highly sensitive magnetoresistive gradiometer sensor Based on studied magnetic field distribution of a magnet, a prototype pressure sensor was designed and fabricated, which consists of a polymer diaphragm, a permanent magnet and a giant magnetoresistance based magnetic field gradient sensor The fabricated prototype was calibrated for ultra-low differential pressure range and it shows: (i) sensitivity up to 1667 μV/V/Pa and (ii) nonlinearity of 15% FS in the range of 0–300 Pa The real time application was demonstrated where, the sensor was flush mounted on a NACA 4415 airfoil, and both the static and the dynamic suction pressures were recorded as a function of the wind velocity and also with different angle of attack (AOA) The measured pressure was found to be highly accurate while compared with existing static measurement system