Bashir Mohamed

Analyzing the effect of cutting parameters on surface roughness and tool wear when machining nickel based hastelloy ? 276

Machining parameters has an important factor on tool wear and surface finish, for that the manufacturers need to obtain optimal operating parameters with a minimum set of experiments as well as minimizing the simulations in order to reduce machining set up costs. The cutting speed is one of the most important cutting parameter to evaluate, it clearly most influences on one hand, tool life, tool stability, and cutting process quality, and on the other hand controls production flow. Due to more demanding manufacturing systems, the requirements for reliable technological information have increased. For a reliable analysis in cutting, the cutting zone (tip insert-workpiece-chip system) as the mechanics of cutting in this area are very complicated, the chip is formed in the shear plane (entrance the shear zone) and is shape in the sliding plane. The temperature contributed in the primary shear, chamfer and sticking, sliding zones are expressed as a function of unknown shear angle on the rake face and temperature modified flow stress in each zone. The experiments were carried out on a CNC lathe and surface finish and tool tip wear are measured in process. Machining experiments are conducted. Reasonable agreement is observed under turning with high depth of cut. Results of this research help to guide the design of new cutting tool materials and the studies on evaluation of machining parameters to further advance the productivity of nickel based alloy Hastelloy – 276 machining.

Investigation on Chip Formation during Machining Using Finite Element Modeling

Titanium alloys are desirable materials for aerospace industry because of their excellent combination of high specific strength, lightweight, fracture resistant characteristics, and general corrosion resistance. Therefore, the chip morphology is very important in the study of machinability of metals as well as the study of cutting tool wear. The chips are generally classified into four groups: continuous chips, chips with built-up-edges (BUE), discontinuous chips and serrated chips. . The chip morphology and segmentation play a predominant role in determining machinability and tool wear during the machining process. The mechanics of segmented chip formation during orthogonal cutting of titanium alloy Ti–6Al–4V are studied in detail with the aid of high-speed imaging of the chip formation zone. The finite element model of chip formation of Ti–6Al–4V is suggested as a discontinuous type chip at lower cutting speeds developing into a continuous, but segmented, chip at higher cutting speeds. The prediction by using finite-element modeling method and simulation process in machining while create chips formation can contribute in reducing the cost of manufacturing in terms of prolongs the cutting tool life and machining time saving.

Effects of Coolants on Improving Machining Parameters while Mach-Inability Titanium Alloy (Ti-6Al-4V): A Review

In this review, present day, the best versatile material Titanium alloy (Ti-6Al-4V) plays the most vital role in the manufacturing of aero engines as a base material. It has been observed that machining this type of alloys is the complicated tasks with optimum machining results. This research investigates the consequences of machining parameters by making use three types of technique: firstly, nitrogen gas technique; secondly, high pressure coolant (HPC); thirdly, cryogenic cooling technique as the coolant’s techniques compared to the normal coolant. Utilizing liquid nitrogen and gas nitrogen as a coolant will decrease friction, heat at the cutting zone, surface roughness, the amount of power consumed in a metal cutting process in addition significantly increase the tool life, dimensional accuracy and so improve the productivity.

Study on Burr Formation Mechanism When Turning Nickel-Based Alloys

The aim of this paper was to introduce the study on burr formation mechanism of nickel-based Hastelloy C-276 in the turning process. The process is monitored using a high-speed camera mounted on a computer numerical control (CNC) turning machine. The captured photographs show that the burr starts appearing on the edge of an uncut surface when the engagement with the chip—workpiece contact area is complete and increases accordingly during the process of hitting the cutting edge and causing chipping wear. The study shows that the initializing of chip burr formation can be divided into two stages: creating and mounting up. Creating of burr formation is characterized by the “reaction of shear formation” of the cutting force on the edge of chip for an unmachined surface, while mounting up increasing in size and forcing the chip to change its direction shoots up the rake face. This edge of the burr will separate and re-attach with the burr edge again during mounting up, thus creating a chain web shape on the edge of the uncut surface and causing edge chipping. The results show that the approach angle has a significant effect on burr formation.

Prediction of High Cutting Speed Parameters forTi-6Al-4V by Using Finite Element Modeling

Titanium alloy (Ti-6Al-4V) is lightweight, corrosion resistant and high-temperature materials. It has the highest strength to weight ratio of all commonly used metals up to 550 C. Machining of titanium alloy (Ti-6Al-4V) by milling operation is widely used in the aerospace industry. High-speed machining processes are of growing industry interest, especially due to appealing feature of high cutting speed processes. The cutting speed is considered as one of the most important factors in the success or failure of any cutting processes. The main purpose of machining modeling is to predict reaction forces (RF), stress components at integration points–Mises, and pressure without need to perform many experimental tests. The tests were performed at various cutting speeds while the depth of cut and feed rate remain constant. The prediction by using finite-element modeling method in machining titanium alloy can contribute in reducing the cost of manufacturing in terms of prolongs the cutting tool life and machining time saving.

Finite Element Modeling for Prediction of Stress – Strain at Several Feed Rates and Cutting Speeds for Titanium (Ti-6Al-4V) Alloy

Titanium (Ti-6Al-4V) alloy is a desirable material for the aircraft industry because of their excellent properties behaves of high specific strength, fracture resistant characteristics, lightweight and general corrosion resistance. This paper presents a study on a two-dimensional orthogonal cutting process by using a face-milling operation through ABAQUS/EXPLICIT finite-element software. Several tests were performed at various feed rates and cutting speeds while the depth of cut remains constant. The results led to the conclusion that the stress components at integration points (Von - Mises) and the equivalent strain (PEEQ) were increased with increasing the feed rate and cutting speed during the machining process.