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ABSTRACT: The design and development of cutting tool for milling requires a number of consideration such as thermal distribution, cutting force and torque applied to the tool, wear, vibration and more. The goal of this research is to design and develop milling cutting Tool. SolidWorks 2020 was used to design the cutting tool, specifically the end mill tool, and static analysis was performed. Using AdvantEdge FEM to simulate the results. Introduction: In milling process, the chip separation process occurs at the edge of the shear zone with lateral plastic flow of material which form burr [1]. The performance of a cutting tool affected by three factors that play the important role: hardness, wear resistance, chemical inertness and fracture toughness of the work piece material [2]. Notching at the tool nose and depth of cutting region was a prominent failure mode when machining nickel-based alloys due to the combination of high temperature, high work piece strength, work hardening and abrasive chips [1]. Special physical condition such as the stress and high temperature gradient most likely to cause tool wear [1]. Tool life is important to save time from replacing the tool and reset the tool during machining [3AISI P20 is milled by using carbide coated insert in the research and it is a high speed steel to machine mould and has the tensile strength of 1044 MPa at room temperature and a hardness ranging from 280 to 320 HB [3-5]. Tool life decreases with the increases of cutting speed, federate, axial depth and radial depth of cut [4]. The chemical composition of the tool also affect the wear rate of the carbide coated tool [1]. When design a cutting tool for milling purposes, there are three main parameters to consider namely temperature distribution during the machining, torque produced and the cutting force exerted on the tool. This is important in order to prevent tool failure. The temperature during the machining can rises up to 1000oC in the cutting zone at the tool-chip interface [6]. In the end milling of AISI 618 stainless steel work piece material using carbide inserts PVD coated with a layer of TiN, the torque measured is as tabulated in Table 1 [7, 8]. From the result, the maximum torque is 23Nm thus the tools to be designed need to be able to withstand torque of more than 23Nm to prevent tool failure. [9] by using Hast alloy C-22HS as work piece material, the cutting force is as shown in Table 2 and from the result, the cutting tools to be designed need to be able to withstand forces of more than 1250N to prevent tool failure. From the experiment by Fuh and Hwang [10], the maximum milling force recorded by using 20mm and 30o helix angle of milling tools is 722.7N. For high speed cutting, the choice of tool materials highly dependent on the wear processes between the work piece and cutting edge [15]. Coating carbide tools initially developed by using Chemical Vapour Deposition (CVD) technique and most of the multi-layer coating materials contain a combination of TiN, TiC, Ti(C,N) and Al2O3 with different deposition sequences to improve tool life [16]. TiC coatings enable high resistance to flank wear, TiN coatings allow little crater wear, A12O3 or ALON remain chemically stable even at high temperatures because of their low avidity, and multiple coatings with ALON show less crater wear [15]. Oxide-coated tools has better performance when use for dry cutting operation [17]. Fracture and chipping occurred approximately 50% of the tool damage cases and it started from the thermal cracks generated in the straight cutting edge [18]. Cryogenic treatment is an extreme cold treating process range -125 to -196oC to improve properties of high precision parts and components such as machining tools as it increases the hardness and improves the hardness homogeneity [19]. Cryogenic treatment of tools able to guarantees their quality after regrinding or re-sharpening unlike coating [21]. Deep cryogenically treated samples of H13 improved the wear properties of the H13 tool steel by forming a uniform and very fine carbide particles [19]. 4 The purpose of this project is to design and develop a cutting tools for milling process. Thus, the important parameters such as the temperature distribution, cutting force and torque acted on the tool during machining were studied to help in the designing stage and simulation of the design. METHODOLOGY: The fatigue analysis on the cutting tool can be performed through an integrated Finite Element (FE) based analysis providing appropriate tool material by using Marrow correction [16-18]. Finite element method able to predict the deformation, stresses and strain in the work piece as well as the load on the tool under the specified cutting parameter [19]. Third wave AdvantEdge is used to model the cutting process of HASTELLOY C-22HS work piece where the element distortion is updated by refining large element, re-meshing distorted elements and corsening small elements [17]. Finite Element Method (FEM)-based techniques can provide more detailed information not only for cutting forces but also for tool stresses and temperatures [18]. Static cutting force increase with axial depths of cut when using a new cutter [19]. The attempt used in this project design and development is to use cryogenic treated H13 tool steel as the material for the end mill as it able to provide a uniform material hardness distribution compared to coated tool which desirable for re-sharpening and regrinding of tool [19]. The modelling of the end mill is designed as detail as possible as simulation end mill geometry by using simple beam models are inaccurate [19]. The designed H13 tool steel end mill is as shown in Figure 3. Figure: 3D modelling of a 25mm diameter and 180mm long end mill generated by using. Static Analysis: Static analysis was performed on the designed end mill to determine the possibility of the tool to break or fail under static loading. The finite element analysis was done by using AdvantEdge FEM Simulation by considering the maximum force and torque exerted on the tool during the cutting process according to the literature studied. The external loadings applied are 26 N/m of torque and 1250 N of forces to one of the tool surface. The physical properties of H13 tool steel used is 7800 kg/m3 density, 1990 Mpa tensile strength, 1650 Mpa yield strength, 0.3 poissons ratio and 81.0 Gpa shear modules. Figure 4 shows the location where the force and torque been applied on the end mill tool to run the simulation. The green coloured arrows indicates the fixture region 5 where the tool is hold in fixed position visualizing the tool holder holding effect to obtain a more realistic result. Figure 4: FEM external load setup (a) force and (b) torque RESULTS AND DISCUSSION: From the simulation by using AdvantEdge FEM Simulation, the result obtained is as shown in Figure 5 below consist of the FOS and resultant displacement in millimeter (mm). Figure 5 (a) shows that the critical region of the design is at the end of the tool holder which has the minimum FOS. It also shows that the particular region is where the stress concentration occurs and extra caution need to be taken in designing and selecting the tool materials. The FOS color tone also shows that the stresses is more in the region where there are changes in geometry of the tool design. On the other hand, Figure 5 (b) shows that the maximum resultant displacement occurs at the tip of the cutting tool edges. From the simulation by using AdvantEdge FEM, the minimum FOS is 12 and the maximum resultant displacement is 0.0969mm as shown in Figure 5. From the result obtained, the tool is less likely to break. Figure: AdvantEdge FEM simulation result (a) FOS and (b) resultant displacement However, in actual practice, it is subjected to dynamic loading, vibration and thermal stress which can causes tool failure. Even a slight vibration may cause the premature failure of the tool [29]. Even the high temperature in tools could cause it to wear rapidly and constraint the tool life [30]. Temperature distribution is important to determine the suitable material for the tool and limit the tool application. CONCLUSIONS: In this study, it was attempted to develop a cutting tool for milling purposes. From the literature study, it was decided to use cryogenic treated H13 tool steel as the material for the end mill as it able to provide a uniform material hardness distribution compared to coated tool. From the simulation, it shows a good result with FOS of 12 and resultant displacement of 0.0969 mm. However, the simulation by using a more specific software such as Thirdwave AdvantEdge is recommended for better result in term of thermal stresses, tool performances and vibration. In conclusion, the objective of this study is achieved
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