Tool Wear Patterns and Their Promoting Mechanisms in Hybrid Cooling Assisted Machining of Titanium Ti-3Al-2.5V/grade 9 Alloy

Industries and researchers are trying to reduce the use of coolant lubricant fluids in metal cutting to obtain safety, environmental and economical benefits. The aim of this research is to determine if the minimal quantity lubrication (MQL) technique in turning gives some advantages in terms of tool wear reduction. This paper reports the results obtained from turning tests and SEM analysis of tools, at two feed rates and two cutting lengths, using MQL on the rake and flank of the tool. The results obtained show that when MQL is applied to the tool rake, tool life is generally no different from dry conditions, but MQL applied to the tool flank can increase tool life.

Minimal Quantity Lubrication in Turning: Effect on Tool Wear

Sustainability aspects of machining operations: A summary of concepts

A review on machining performance of AISI 304 steel

Machinability performance investigation in CNC turning of Ti-6Al-4V alloy: Dry versus Iron-aluminium oil coupled MQL machining comparison

Nanocutting fluids are very popular due to their excellent thermo-physical and tribological properties which provide adequate cooling and lubrication during metal cutting. Conventional dry machining of difficult-to-cut superalloy Ti–6Al–4V faces several challenges. To overcome this, application of cutting fluid is indeed a necessity. However, performance of conventional minimum quantity lubrication (MQL) system, in which air–oil mist is sprayed into cutting zone, is somewhat limited due to inadequate penetration into tool–work and tool–chip interfacial regions, especially at high cutting speeds. MQL performance can further be enhanced by applying nanocutting fluid in which nano-sized additives are dispersed into the base cutting fluid; this is known as nanofluid MQL (NFMQL). In order to take care of several alarming issues related to environmental protection and occupational health hazards, the present study explores application feasibility of biodegradable Jatropha oil added with graphene nanoplatelets as nanocutting fluid. Machinability of Ti–6Al–4V is assessed under NFMQL; results are compared to that of dry and conventional MQL machining. Cutting force magnitude, tool-tip temperature, morphology of worn-out insert, chip’s macro/micro-morphology and surface roughness of the machined work part, etc., are studied in detail. For MQL and NFMQL, tool wear morphology detects existence of ‘unaffected zones’ which indicates sustenance of strong hydrodynamic tribo-film of cutting fluid, thus protecting the insert against wear. Up to 82 m/min cutting speed, NFMQL causes lower tool flank wear than dry and conventional MQL. On the other hand, superior machined surface finish is obtained under NFMQL up to 106 m/min cutting speed.

Dry, MQL, and Nanofluid MQL Machining of Ti–6Al–4V Using Uncoated WC–Co Insert: Application of Jatropha Oil as Base Cutting Fluid and Graphene Nanoplatelets as Additives

The present study examines dry machining performance of AA7075 T6 alloy using uncoated and MT-CVD TiCN–Al2O3-coated carbide inserts. Machining performance is assessed with regard to tangential cutting force, tool tip temperature and depth of flank wear. The performance of coated tool is compared to that of uncoated insert. In addition, different modes of tool wear and chip morphology are studied in detail. It is experienced that coated tool causes lower tool tip temperature and lesser flank wear than untreated counterpart. Apart from abrasion, adhesion and built-up layer formation; attrition wear is distinctly visible in case of uncoated tool. On the contrary, in addition to common wear modes, coated tool also experiences diffusion wear.

Dry Machining Performance of AA7075-T6 Alloy Using Uncoated Carbide and MT-CVD TiCN-Al2O3-Coated Carbide Inserts

In the present investigation, machining performance of Ti6Al4V is studied under dry environment, pressurized air supply and distilled water based Minimum Quantity Lubrication (MQL). Machining (turning) performance is assessed in purview of cutting force (tangential component) magnitude, tool-tip temperature, width of tool flank wear progression, morphology of evolved chips and severity of vibrations at varied cutting speeds as well as cooling media. Characteristic features of spatial temperature distribution profile (at the vicinity of tool-tip) as influenced by varied cooling media are studied with the help of thermographs of the cutting zone. Mechanisms of cutting tool wear are studied as well. It is experienced that amongst three cutting environments tested, application of water-MQL is beneficial for machining of Ti6Al4V at low cutting speed. Severity of vibrations gets 50.39% reduced during machining under water-MQL than dry condition. Consequently, as compared to dry machining, water-MQL causes 79% reduced tool flank wear and 82% reduced crater wear at low cutting speed. Under water-MQL, reduced tool-tip temperature (66% reduced than dry condition) suppresses severity of tool wear. In comparison with high cutting speed, performance of water-MQL is found much better at low cutting speed. ‘Unaffected zones’ are identified at the worn-out tool rake face under water-MQL. High amplitude of vibration (maximum absolute mean value) causes low chip-segmentation ratio. On the contrary, chip reduction coefficient gets truncated with decrement in vibration amplitude. Vibration amplitude has positive influence on degree of chip-curl.

Machining performance of Ti6Al4V under dry environment, pressurized air supply and water-MQL: analysis of machining-induced vibration signals and captured thermographs

Sarthak Prasad Sahoo

Papers

Dry, MQL, and Nanofluid MQL Machining of Ti–6Al–4V Using Uncoated WC–Co Insert: Application of Jatropha Oil as Base Cutting Fluid and Graphene Nanoplatelets as Additives

Dry Machining Performance of AA7075-T6 Alloy Using Uncoated Carbide and MT-CVD TiCN-Al2O3-Coated Carbide Inserts

Machining performance of Ti6Al4V under dry environment, pressurized air supply and water-MQL: analysis of machining-induced vibration signals and captured thermographs

Influence of cutting speed on dry machinability of AISI 304 stainless steel

Machining behaviour of Inconel 825 under distilled water based minimum quantity lubrication