Performance of carbide insert in turning of titanium alloy under carbon dioxide cryogenic cooling

In manufacturing industries, such as aerospace, automotive, chemical and medical, the application of titanium alloys has received more attention, especially in dental implant and orthopedic implant. Although this titanium alloy has a unique characteristics, such as difficulties to machining due to high hardness, lower thermal conductivity and higher chemical reactivity, this material is always in high demand. During machining of titanium alloy, the major issues frequently discussed are rapid cutting tool wear and generation of high cutting temperature. The proper cooling method needs to be used in order to reduce high cutting temperature that causes rapid tool wear thus increases the tool life of the cutting tool during machining titanium alloy. Many studies have been reported by researchers of cryogenic cooling in machining titanium. In this research, an attempt has been made to investigate the effect of cryogenic cooling using carbon dioxide (CO2) liquid, when it is applied to the workpiece and cutting tool during turning of titanium alloy Ti–6Al–4V ELI. The operation process was carried out using a 3-axis CNC Haas ST-20 lathe machine. Response Surface Methodology (RSM) has been used to design the experiment in determining the effect of the cutting parameters: cutting speed, feed rate and depth of cut towards tool life of the uncoated carbide insert. From RSM, Box-Behnken design has been selected to arrange the cutting parameters of cutting speed with range of 120 to 220 m/min, feed rate with 0.1 to 0.2 mm/rev and depth of cut is 0.4 to 0.6 mm. The flank wear was measured using tool maker microscope. The cutting time values were recorded for each 20 mm on the workpiece until flank wear (Vb) reaches the tool life criterion followed by JIS B4011-1971 standard. From the experiment, the longest tool life recorded is 17.58 minutes obtained at cutting speed 120 m/min, feed rate 0.15 mm/rev and depth of cut 0.40 mm. The shortest tool life is 0.45 minutes obtained at the cutting speed 220 m/min, feed rate 0.15 mm/rev and depth of cut 0.6 mm. The ANOVA analysis showed that for tool life, cutting speed is the most significant factor followed by feed rate and depth of cut to determine and optimise the tool life values. From the detailed observation using SEM, it can be concluded the tool failure mode presents at the cutting tool are flank wear and crater wear. In addition, the observed dominant wear mechanism at the cutting tool is abrasion and adhesion

Performance Of CVD Coated Carbide Tool By Optimizing Machining Parameters During Turning Titanium Alloy Ti-6AL-4V ELI In Flooded Condition

In metal cutting, one of the important elements which must seriously consider is cutting tools. Carbide cutting tool is widely used in machining process for various metal types. This paper presents the performance of cutting tools in turning Ti-6AL-4V ELI using the CVD coated carbide tool under flooded conditions. Experimental design of this study is based on Factorial method. Two Level Factorial designs were selected to arrange the cutting parameters of cutting speed with a range of 100 to 140m/min, feed rate with 0.15 to 0.20mm/rev, and depth of cut was kept constant at 0.35mm. Flank wear was measured using a three axis microscope. The values were recorded for each length of the workpiece until flank wear (Vbavg) average reaches the tool life criterion, Vbavg = 0.3mm followed by International Standard ISO 3685. From the result obtained, it is found that lowest cutting speed and feed rate resulted in longer tool life while highest cutting speed and feed rate resulted in a much shorter tool life. Based on the ANOVA analysis, cutting speed is the most significant factor followed by feed rate. Mathematical modelling was developed and the error between experimental results and generated model is 19%. The optimum responses are obtained at cutting speed 100m/min, feed rate 0.15mm/rev, and this give out the longest tool life of 15.43minutes while shortest tool life, 4.07 minutes was obtained at cutting speed of 140m/min and feed rate 0.20 mm/rev. The error value of optimization between experimental and model is 0.19%. From this research, even though titanium alloy, Ti-6Al-4V is considered as material with low machinability, there are suitable cutting parameters available to give out the longest tool life thus reducing machining cost

The Effect Of Cryogenic Cooling On Surface Roughness Of Titanium Alloy: A Review

Titanium alloy is a unique material that can maintain its high strength–weight ratio during elevated temperatures. It is one of the important metal parts of the engine components and aircraft structural. Surface roughness is one of the important parameters used in evaluating the quality of finish machined surfaces because of these parts of components in aerospace industry are manufactured to reach high consistency level. To improve the surface roughness of the work materials, the use of coolant in manufacturing operations such as turning process must be considered properly. The application of cryogenic coolant in machining process was analyzed in details in this review. The study was based on the application methods in machining operations which is the turning process on titanium alloy and the condition of work materials by looking at surface roughness values when using the coolant. The findings showed the most constructive method for machining operations was cryogenic cooling. This is because of its capability in producing better surface finishes by reducing the cutting temperature during machining operation, subsequently, enhancing the quality and function of the products or components