Investigation of boring on gunmetal in dry, wet and cryogenic conditions

Abstract

Secondary operation of boring is carried out to produce close geometric tolerance holes produced in drilling. In this work, an attempt has been made in producing a hole by dry boring, wet boring and cryogenic boring of gunmetal. Gunmetal finds its application in areas of casting, steam turbines and pressure valves, due to its high resistance to corrosion. Investigation of cutting temperature generated during machining, cutting force experienced by the tool and surface roughness of the machined workpiece was toted out with analogous to cutting speed and feed, by Taguchi, ANOVA and TOPSIS analyses. Surface morphology study, tool wear analysis, residual stress analysis were done in order to distinguish the modification in the bored surface and tool material after machining. Cryogenic boring of gunmetal reduced the cutting temperature by 63.43% and 53.85% over dry boring and wet boring, respectively. Furthermore, cutting force is reduced by 34.51% and 18.29% over dry boring and wet boring, respectively. Additionally, a decrease of 62.23% and 35.10% is observed in surface roughness on comparing dry boring and wet boring with respect to cryogenic boring of gunmetal. Taguchi and ANOVA arbitrated speed as an imperative parameter for cutting force and feed as a paramount parameter in cutting temperature. Furthermore, speed is a crucial parameter for arbitrating surface roughness in dry boring and wet boring, additionally feed for surface roughness in cryogenic boring condition. TOPSIS analysis illuminated speed of 1200 rpm and feed of 0.055 mm/min as the most closest to exemplar elucidation for all three cutting preconditions. Aggrandizement in compressive residual stress is discerned in cryogenic boring by 39.74% and 19.35% correlated with dry boring and wet boring, respectively, as the material undergoes work hardening. A decrease in residual tensile stress is espied in cryogenic boring when juxtaposed to wet boring, ensuring upsurge in tool life and better surface characteristics. Microhardness in cryogenic boring of gunmetal improves by 5.83-11.05% and 0.51-2.57% analogous to dry boring and wet boring, respectively. Corrosion resistance in cryogenic boring increases by 77.43% and 49.25% analogous to dry boring and wet boring of gunmetal, respectively. The circularity and cylindricity increase by 4.76-98.40%, 8.33-97.50% and 6.25-97.15%, 2.43-92.85% in cryogenic boring juxtaposed to dry boring and wet boring of gunmetal, respectively.

Experimental investigation of the electrochemical micromachining process of Ti-6Al-4V titanium alloy under the influence of magnetic field

“…By utilizing multi-attribute algorithms, scientists have established various decision-making statistical tools. The most common of them are ELEC-TRE [27], TOPSIS [28], GREY [29], and VIKOR [30]. TOPSIS, among them, holds its ground as it evaluates with minimal variation, has a lower computational complex and ensures that a common vertices plane is obtained, which postulates a close to ideal solution and negates the far from ideal solution [31].…”

Experimental Investigation of Dry and Cryogenic Friction Stir Welding of AA7075 Aluminium Alloy

“…Careful thermal insulation is done with help of foam (polymer in nature) in order to prevent being affected by external heat during the transfer. e nozzle is availed to point the fluid towards the friction stir welding zone [12,[14][15][16][17][18][20][21][22]]. An AWM720P1 flow sensor is availed to ensure a constant volume flow rate for liquid nitrogen at 1 bar pressure atmospheric pressure which is 1.977 litres/minute, by taking the total head loss in consideration, elevation point of the FSW setup, and having initial velocity and exit pressure to be zero.…”

“…Conditions. For performing friction stir welding of AA 7075 aluminium alloys in the dry and cryogenic environment, orthogonal (L 27 ) array is availed [5,15,19,[21][22][23][24][25] after running an in-depth preliminary testing before finalizing on the working range for the input factors. e parameters taken in consideration are microhardness and tensile strength in correlation to tool pin profile, pipe rotation speed, welding speed, and axial force applied on the parent material.…”

“…Analysing and applying multiattribute algorithms, researchers have established disparate methods of solving the multiple attribute-response problem. e commonly availed technique is ELECTRE, GREY, TOPSIS, and VIKOR [12,13,15,19,[21][22][23][24][25] in which TOPSIS holds a higher ground due to its simplicity in adapting, minimal variation, and drop in complexity with involvement of multiple vectors (provides a common vector plane solution). e method adopted for analyzing the attributes and responses is indicated in Figure 11.…”

“…From the criteria analysis (preference to unity factor), tool profile stepped type, pipe rotation speed of 1000 rpm, welding speed of 50 mm/min, and axial force of 8 kN are close to unity, i.e., ideal solution for dry and cryogenic friction stir welding of AA 7075 aluminium alloys [12,15,19,[22][23][24][25]. ese close to ideal samples are taken to study the individual microstructural properties affecting the welding zone in disparate environmental conditions.…”