Recent advancements in nano-lubrication strategies for machining processes considering their health and environmental impacts

Industries have been seeking an efficient lubrication system that meets the requirement of sustainability without compromising manufacturing efficiency or final part quality. Conventional cutting fluids have been recognized as hazardous to the environment, health and economy of industries. The nano lubrication strategy has emerged as a sustainable and power-efficient lubrication system with encouraging performance in machining processes. This paper encapsulates an overview of the impact regarding usage of nanofluid as a cutting fluid in different machining processes. The recent innovations in the past decade, altered nano lubrication systems have been briefly summarized. A state of art review commences with a short synopsis of the historic perspective followed by a summary of the impact of nanofluid on different machining processes. The discussion section has been bifurcated according to the characterization of machining performance metrics. The environmental and health issues that emerged with the use of nanofluid are then discoursed thoroughly. Finally, the major findings are summarized and the future scope of research is identified. It can be quantified that the implementation of a nano lubrication system can significantly improve the heat transfer characteristic of base fluid which ultimately leads to the functionally tremendous product. However, there are major unknowns related to the health and environmental impact of nanoparticles

Symbiotic characters, thermal requirement, growth, yield and economics of pigeonpea (Cajanus cajan) genotypes sown at different dates under Punjab conditions

A field experiment was conducted during kharif (rainy season) 2008 and 2009 at research farm of the Punjab Agricultural University, Ludhiana, to study the effect of four/three sowing dates (1 May, 15 May, 1 June and 15 June in 2008 and 15 May, 1 June and 15 June in 2009) on the symbiotic characters, thermal requirement, growth, productivity and economics of four pigeonpea genotypes (AL 201, AL 1507, AL 1578 and AL 1593). Days taken to 50% flowering, physiological maturity, and various agroclimatic indices i.e. AGDD, AHTU, APTU and HUE decreased with delay in sowing. The crop sown on 15 May recorded the highest nodule dry weight plant -1. The grain yield was significantly higher for the 15 May sowing compared to the 15 June sowing. During the two years, the crop sown on 15 May registered on average 6.7 and 48.0 percent higher grain yield than the1 June and 15 June sowings, respectively. The crop sown on 15 May gave the maximum gross returns, net returns and benefit-cost (B:C) ratio. Among the genotypes, AL 1507 recorded the highest nodule number plant-1 and AL 1578 recorded the maximum nodule dry weight plant-1.Genotypes AL 1507, AL 1578 and AL 1593 registered on average 19.4, 19.2 and 20.0 percent higher grain yield relative to AL 201, respectively. The genotype AL 1507 in 2008 and AL 1593 in 2009 performed better in terms of heat use efficiency for grain yield

Tool Wear Analysis during Ultrasonic Assisted Turning of Nimonic-90 under Dry and Wet Conditions

Nickel-based superalloys are widely used in the aerospace, automotive, marine and medical sectors, owing to their high mechanical strength and corrosion resistance. However, they exhibit poor machinability due to low thermal conductivity, high shear modulus, strain hardening, etc. Various modifications have been incorporated into existing machining techniques to address these issues. One such modification is the incorporation of ultrasonic assistance to turning operations. The assisted process is popularly known as ultrasonic assisted turning (UAT), and uses ultrasonic vibration to the processing zone to cut the material. The present article investigates the effect of ultrasonic vibration on coated carbide tool wear for machining Nimonic-90 under dry and wet conditions. UAT and conventional turning (CT) were performed at constant cutting speed, feed rate and depth of cut. The results show that the main wear mechanisms were abrasion, chipping, notch wear and adhesion of the built-up edge in both processes. However, by using a coolant, the formation of the built-up edge was reduced. CT and UAT under dry conditions showed an approximate reduction of 20% in the width of flank wear compared to CT and UAT under wet conditions. UAT showed approximate reductions of 6–20% in cutting force and 13–27% in feed force compared to the CT process. The chips formed during UAT were thinner, smoother and shorter than those formed during CT

Review on machining of additively manufactured nickel and titanium alloys

The machining of nickel and titanium-based superalloy components is very expensive and involves unusually high lead times compared with other engineering metals such as steels and aluminum. This has led to the development of most suitable additive manufacturing (AM) processes to fabricate these difficult-to-machine metals into near-net shape parts, thereby reducing the lead time and material waste, and significantly increasing productivity. Nonetheless, finish machining is still required on the AMed metal components to meet the dimensional and surface requirements of the application. Several research studies have investigated the machinability of AMed nickel and titanium alloy workpieces and have compared the results with the machining responses of wrought counterparts, which is detailed in this review. The categorization of the literature is based on the machining operations including turning, milling, drilling, and non-conventional machining, and the observations are discussed in accordance with various input parameters such as workpiece characteristics (hardness, microstructures) and anisotropy in mechanical properties due to build orientations during the AM process. Moreover, the influence of these parameters on cutting forces and temperatures, chip formation, and tool wear is analyzed and reported. From this review, it is found that the machinability of AMed nickel and titanium workpieces is quite different to the machining responses of their wrought counterparts. Further thorough experimentation is required to develop optimized machining parameters for AMed metal parts, while an exploration of different cutting tool geometries, coolant, and lubrication strategies for enhanced tool performance for machining AMed workpieces is essential. Finally, this study reviews the state of contemporary research, and offers suggestions for future research

Comparison of dry and liquid carbon dioxide cutting conditions based on machining performance and life cycle assessment for end milling GFRP

In the present scenario, citizens' concern about environment preservation creates a necessity to mature more ecological and energy-efficient manufacturing processes and materials. The usage of glass fiber reinforced polymer (GFRP) is one of the emerging materials to replace the traditional metallic alloys in the automotive and aircraft industries. However, it has been comprehended to arise a sustainable substitute to conventional emulsion-based coolants in machining processes for dropping the destructive effects on the ecosystem without degrading the machining performance. So, in this study, the comparison of the two sustainable cutting fluid approaches, i.e., dry and LCO2, has been presented based on machining performance indicators like temperature, modulus of cutting force, tool wear, surface roughness, power consumption, and life cycle assessment (LCA) analysis for end milling of GFRP. The cutting condition of LCO2 has been found to be superior in terms of machining performance by providing 80% of lower cutting zone temperature, tool wear, 5% lower modulus of cutting force, and reduced surface roughness with 9% lower power consumption that has been observed in the case of LCO2 in comparison with dry machining. However, to compress the CO2 for converting in liquid form, a higher amount of energy and natural resources is consumed resulting in a higher impact on the environment in comparison with dry machining. Considering the 18 impact categories of ReCiPe midpoint (H) 2016, 95% higher values of impacts have been observed in the case of LCO2 in comparison with dry machining.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The authors received financial support from Basque Government in the Excellence University Group system call, grant IT 1573-22

An insight into the effect surface morphology, processing, and lubricating conditions on tribological properties of Ti6Al4V and UHMWPE pairs

The effects of surface topography, processing, and environment conditions during tribological contact between Ti6Al4V titanium alloy and UHMWPE friction pairs were systematically evaluated. Hence, in this research the polyethylene samples (blocks) having a constant surface roughness were rubbed against counter-bodies (rollers) made of titanium alloy with different roughness of surfaces. The counter-samples were manufactured using either dry machining and/or minimum quantity lubrication (MQL) conditions. Such cutting conditions are harmless to humans and the environment. Simulated body fluid (SBF) and distilled water was used to simulate the tribological trials. We have noted that the lubricant applied to protect the integrity of machined parts, the rollers, have only minor impact on the tribological features of the friction pairs tested. Further, the samples produced with dry machining demonstrated a slightly lower momentary friction coefficient and temperature. In contrast, the MQL method enable reduced friction surface and significant wear accumulation. Further, it was found that the minimum and maximum values of the Sa texture parameter associated to tribological parameters do not exceed 21% and 4%, when is used dry and MQL methods, respectively. Nevertheless, the distilled water revealed a much better wear resistance when comparing to SBF, and the later one trigger as well as an accentuated wear progress with different patterns. The results of the study are important in the design of new biomedical components produced by finish turning

GDPR: Six principles of GDPR

GDPR was enacted on 25 May 2018 and has impacted NZ businesses in a big way. The poster presents 6 key principles analyzed from the statues of the regulation for easy consumption of the business owners in NZ. As a part of limited research done in the last 6 months on Privacy in general and GDPR in particular, we propose to come up with a tool that can assist small or medium businesses in New Zealand towards abiding with GDPR. We plan on incorporating this into existing framework that will form a first step towards GDPR compliance

Comparison of Machining Performance under MQL and Ultra-High Voltage EMQL Conditions Based on Tribological Properties

This novel work presents the comparison of a newly developed ultra-high voltage electrostatic minimum quantity lubrication (EMQL) using a customized nozzle with the MQL technique as an alternative cooling/lubricating method in turning processes of 15-5 PHSS. The optimum voltage for EMQL within the range of 0-25 kV has been identified based on tribological performance. Besides, surface roughness has been measured to identify the impact of electrostatically charged mist for turning 15-5 PHSS. Finally, tool wear tests are performed for MQL and EMQL at optimized voltage. The EMQL at optimized electrostatic voltage resulted in 38% decreased tool wear as compared to conventional MQL for 2400 mm cutting length

Development of a Sustainability Assessment Algorithm and Its Validation Using Case Studies on Cryogenic Machining

This work presents a comprehensive structure for evaluating the sustainability of machining processes. Industries can contribute towards developing a sustainable future by using algorithms that evaluate the sustainability of their processes. Inspired by the literature, the proposed model involves a set of metrics that are critical in evaluating the impact of a process on society, environment, and economy. The flexibility of this model allows decision-makers to use the available responses to identify the most favorable process. The entropy weight method was suggested for objectively calculating the weights of each indicator. A multi-criteria decision-making method i.e., Technique for Order Preference based on Similarity to Ideal Solution (TOPSIS), was used to rank processes in the decreasing order of their sustainability. The proposed algorithm was successfully validated with case studies from the published literature. A MATLAB code was also created so that industries may expeditiously apply this method to evaluate the sustainability of machining processes