Gusri Akhyar Ibrahim

Tool Wear Mechanism in Continuous Cutting of Difficult-to-Cut Material under Dry Machining

Wear mechanism on the flank of a cutting tool is caused by friction between newly machined surface and the cutting tool, which plays predominant role in determining tool life. Detailed study on wear mechanism at the cutting edge of carbide tools were carried out at cutting speed of 55 – 95 m/min, feed rate of 0.15 – 0.35 mm/rev and depth of cut of 0.10 – 0.20 mm. The wear on the cutting tools was occurred predominantly on the nose radius, as effect of lower feedrate and nose radius selected. Various wear observed on both coated and uncoated cutting tool such as abrasive wear, adhesive wear, adhering chip on the cutting edge, flaking, chipping, coating delamination of coated tool, crack and fracture. The abrasive wear predominantly occurred on the flank face while the flaking on the rake face. Abrasive wear occurred at nose radius due to the depth of cut selected was low therefore, the contact area between the cutting tool and the workpiece material was small. Adhesion or welded titanium alloy onto the flank and rake faces demonstrated a strong bond at the workpiece-tool interface. The adhesion wear takes place after the coating has worn out or coating delamination has been occurred. The crack occurred possibly due to machining at high cutting speed and high depth of cut. Cutting at high cutting speed caused more heat generated at the cutting edge and at high depth of cut caused more cutting forces on the insert.

Surface integrity of AISI D2 when turned using coated and uncoated carbide tools

Surface integrity of tool steel AISI D2 was studied to investigate the surface roughness, surface topography and surface hardness at various machining parameters. Coated carbide (KC 9125) and uncoated carbide (K 313) were used in turning tool steel AISI D2 bar with hardness of 25 HRC. Machining tests were performed in dry cutting condition at various cutting speeds and feed rates while the depth of cut was kept constant. Taguchis design of experiment was employed to accommodate the machining parameters of various cutting speeds and feed rates. Results show the surface roughness for uncoated carbide tools in range of 0.36?4.05 ?m and coated carbide tools in range of 0.30?1.51 ?m. The lowest surface roughness value for both types of carbide tools were observed at cutting speed of 250 m/min and feed rate of 0.05 mm/rev. Martensitic white layer was found at 170 ?m underneath machined surface.

Performance of PVD-Coated Carbide Tools When Turning Inconel 718 in Dry Machining

Inconel 718 has found its niche in many industries, owing to its unique properties such as high oxidation resistance and corrosion resistance even at very high temperatures. Coated carbide tool with hard layer of PVD TiAlN is used to turn Inconel 718. Taguchi method with the orthogonal array L9 is applied in this experiment with the parameter cutting speed of 60–80 m/min, feed rate of 0.2–0.3 mm/rev, and depth of cut of 0.3–0.5 mm. The results show that depth of cut is a significant influence to the tool life. Cutting speed of 60 m/min, feed rate of 0.2 mm/rev, and depth of cut of 0.3 mm are the optimum parameters. The flank wear, crater wear, notch wear, and nose wear are the wear mechanisms on the carbide tool. Through the SEM, abrasion, attrition, and adhesion are the wear mechanisms which can be seen on the cutting tool.

Surface Intergrity of Inconel 718 under MQL Condition

The purpose of this study is to investigate the effect of turning parameters on the surface integrity of Inconel 718. The turning parameters studied were cutting speed of 90, 120, 150 m/min, feed rate of 0.15, 0.25, 0.25mm/rev and depth of cut of 0.3, 0.4, 0.5 mm under minimum quantity lubricant (MQL) using coated carbide tool. surface response methodology (RSM) design of experiment using Box-Behnken approach has been employed consisting of various combination of turning parameters Surface roughness, surface topography, microstructure and the micro hardness of the machined surface were studied after the machining process. Feed rate was found to be the most significant parameter affecting the surface roughness. The optimum parameter was obtained with Ra equal to 0.243 µm at cutting speed of 150 m/min, feed rate of 0.25 mm/rev and depth of cut of 0.3mm. A mathematical model for surface roughness was developed using Response Surface Methodology. The effect of turning parameters and factor interactions on surface roughness is presented in 3D graphical form, which helps in selecting the optimum process parameters to achieve the desired surface quality.

Sustainable rural energy: traditional water wheels in Padang (PWW), Indonesia

The traditional water wheel with simple construction coupled with a basic concept of technology can be utilised as a renewable rural energy system. Water wheel is constructed from hardwood material with a diameter of 300 cm and width of 40 cm. It is built on a river using water flow to generate the movement of the wheel. The water wheel application in the area showed that it is suitable to be utilised to elevate and distribute water to rice fields located at a higher level than the water level of the river. The water wheel capacity is about 100 – 120 litres/min. It could continuously irrigate ± 5 ha. of the rice fields. One of the advantages of this water wheel is to function as a green technology promising no negative effect on the environment and a big economic impact on the rural economy, increasing the productivity of the rice fields.

Evaluation of PVD-inserts performance and surface integrity when turning Ti-6Al-4V ELI under dry machining

The great advancement in the development of carbide cutting tool with super-hard coating layers taken place in recent few decades, can improve the performance of cutting tool and machinability of titanium alloy. The turning parameters evaluated are cutting speed (55, 75, 95 m/min), feed rate (0.15, 0.25, 0.35 mm/rev), depth of cut (0.10, 0.15, 0.20 mm) and tool grade of PVD carbide tool. The results that tool life shows patterns of rapidly increase at the initial stage and gradually increased at the second stage and extremely increased at the final stage. The trend lines of surface roughness have are the surface roughness value is high at first machining after that regularly decreases. Work hardening of the deformed layer beneath machined surface caused higher hardness than the average hardness of the base material. However, the softening effect also occurred below the machined surface. Segmentation or serration at the chip edge was caused by high strain and pressure during machining.

Tool Wear Performance of CVD-Insert during Machining of Ti-6%Al-4%V ELI at High Cutting Speed

Machining of titanium alloys as aerospace material that has extremely strength to weight ratio and resistant to corrosion at high-elevated temperature, become more interested topic. However, titanium alloys have low thermal conductivity, relative low modulus elasticity and high chemical reactivity with many cutting tool materials. The turning parameters evaluated are cutting speed (55, 75, 95 m/min), feed rate (0.15, 0.25, 0.35 mm/rev), depth of cut (0.10, 0.15, 0.20 mm) and tool grade of CVD carbide tool. The results that pattern of tool life progression is rapidly increase at the initial stage. It was due to small contact area between the cutting tool and the workpiece. At the first step of machining, the chip welded at the cutting edge but some chip removed away from the cutting edge. Wear mechanism produced are abrasive wear, adhesive, flaking, chipping at the cutting edge and coating delamination.

Sustainable Rural Energy: Traditional Water Wheels in Padang (PWW) Indonesia

The traditional water wheel with simple construction coupled with a basic concept of technology can be utilised as a renewable rural energy system. Water wheel is constructed from hardwood material with a diameter of 300 cm and width of 40 cm. It is built on a river using water flow to generate the movement of the wheel. The water wheel application in the area showed that it is suitable to be utilised to elevate and distribute water to rice fields located at a higher level than the water level of the river. The water wheel capacity is about 100 – 120 litres/min. It could continuously irrigate ± 5 ha. of the rice fields. One of the advantages of this water wheel is to function as a green technology promising no negative effect on the environment and a big economic impact on the rural economy, increasing the productivity of the rice fields.