N. M. Warap

Laser Assisted Machining of Titanium Alloys

Laser assisted machining is categorized in preheat machining process. The laser beam used to heat up work materials is very flexible in providing a localized heat area. However the combination between two processes which has totally different fundamental has contributed to complex processing characteristics. In the case of hard to machined metal processing, problems in surface integrity and accuracy are frequently arise. Tool ware and work material properties changes are some of the issue that drove engineers and researchers to seek for optimized processing parameters. This chapter introduces resent finding in research done on laser assisted machining (LAM). Focus is given on laser assisted mechanical machining consist of laser assisted milling (LAM) and laser assisted turning (LAT).

Thermal-Assisted Machining of Nickel-based Alloy

Nickel-based alloy can be found in different industrial applications especially in aircraft engines and hot end components of various types of gas turbines with its high strength, strong corrosion resistance and excellent thermal fatigue properties and thermal stability compared to conventional materials. However, nickel-based alloy is one of the extremely difficult-to-cut materials. During the machining process, the interaction between the tool and the workpiece causes severe plastic deformation and intense friction at the tool-workpiece interface. Because of the increasing demands in industries, any improvement of conventional machining processes or any other deployment of additional technique is directly related to higher productivity. Thermal-assisted machining (TAM) has become an effective alternative to the conventional machining of these difficult-to-cut materials. Various types of heating methods and the beneficial effects on machining of nickel-based alloys are discussed in this chapter. Finally, TAM was proven as an efficient technique to increase the machinability of nickel-based alloys in terms of tool life, surface roughness and cutting force.

Numerical Analysis of Laser Heating for Laser Assisted Micro Milling Application

The promising processing techniques of micro scale parts are very important in products miniaturization and functions enhancement. Combination of two or more processing techniques gives better processing performance especially when dealing with difficult-to-cut materials. For that reason, the combination of laser beam and micro milling process has been widely studied and proven efficient in reducing cutting force and tool life extension. However, this process needs a precise temperature control in order to eliminate heat effect generated by laser beam irradiation. In this study, temperature distributions are determined numerically to characterize the melted zone and heat affected zone geometry. From the results, the estimation of tool and micro milling cutter distance together with the allowable depth of cut are determined.

Numerical analysis of laser preheating for laser assisted micro milling of Inconel 718

Micro milling of super alloy materials such as nickel based alloys such as Inconel 718 is challenging due to the excellent of its mechanical properties. Therefore, new techniques have been suggested to enhance the machinability of nickel based alloys by pre-heating the workpiece’s surface to reduce its strength and ductility. The prediction of fluctuated temperature distribution generated by pulsed wave laser in laser assisted micro milling (LAMM) is crucial. The selection of processing parameter by minimize the effect on the processing characteristic is decisive to ensure the machining quality is high. Determining the effect of heat generated in underneath surface is important to make sure that the cutting tools are able to cut the material with maximum depth of cut and minimum defects in terms of tool wear and tool life. In this study the simulation was carried by using Ansys APDL. In order to confirm the actual and distribution irradiation of temperature from simulation, an experimental was done to validate the results. The experiment was conducted by using Nd:YAG laser with wavelength 1064 nm.

Investigation on Laser Assisted Micro Ball Milling of Inconel 718

Micro milling of super alloy materials such as nickel based alloys is challenging due to the excellent of its mechanical properties. Therefore, new techniques have been suggested to enhance the machinability of nickel based alloys by pre-heating the workpiece’s surface to reduce its strength. Determining the processing parameters and their effects to the processing characteristics are crucially important. However, not only the micro-milling parameters need to be considered, but the pre-heating parameters are also need to take into consideration as well. These parameters are expected to improve the machinability. In this study, the experiment of LAMM in Inconel 718 was conducted with considering laser power, cutting speed, depth of cut, feed rate and laser-to-cutting tool distance. From the result, the effectiveness of laser assisted and cutting parameter in term of cutting force and tool wear was identified by comparing between conventional and LAMM. Finally, the optimum range of machining parameters can be determined.

Laser Assisted Micro-Groove Ball Milling of Ti6Al4V

In micro scale, the size of cutting tool and shape significantly contributed to the machining performance. Many studies have been done to improve the cutting tool life and machined surface quality. Problems could become more severe when the workpiece has a low thermal conductivity while having high level of ductility such as titanium alloy. In this study, micro ball mill cutting tool is selected to produce a linear groove on a titanium alloy plate. The process is integrated with a laser source as a pre-heating element on the work piece surface. The condition of the flank surface of the tools and cutting force were observed and discussed. The influence of tool orientation and laser heating parameters in laser assisted micro ball milling (LAMM) were also discussed. It was found out that adhesion is the dominant tool wear mechanism thus fluctuate the cutting force value.

Determination of Heat Flux Intensity Distribution and Laser Absorption Rate of AISI D2 Tool Steel

The prediction of fluctuated temperature distribution generated by pulsed wave laser in laser assisted micro milling (LAMM) is crucial. The selection of processing parameter by minimize the effect on the processing characteristic is decisive to ensure the machining quality is high. Determining the effect of heat generated in underneath surface is important to make sure that the cutting tools are able to cut the material with maximum depth of cut and minimum defects in term of tool wear and tool life. In this study the simulation was carried by using Ansys APDL. In order to confirm the actual and distribution irradiation of temperature from simulation, an experimental was done to validate the results. The experiment was conducted by using Nd:YAG laser with wavelength 1064 nm.

A prediction of laser spot-to-cutting tool distance in laser assisted micro milling Inconel 718

Abstract Laser assisted micro milling (LAMM) is one of the techniques used to enhance the ability to manufacture microscale products. Laser is used to preheat the workpiece materials prior the machining process. Compared with conventional machining, LAMM is a green manufacturing method due to reduction in cutting force during machining process. However, it needs to be controlled to avoid the melting and changing of materials properties. Determining the processing parameters and their effects on the processing characteristics, temperature measurement and the laser spot-to-cutting tool distance are crucially important. In this study, finite element analysis using ANSYS software was used to predict the heat distribution to characterise the melting and heat affected zone formation. The data at the centre of laser spot were recorded to obtain the appropriate distance between laser spot-to-cutting tool. From the results, the estimations of laser spot-to-cutting tool distance of Inconel 718 together with the allowable depth of cut were determined and applied in the actual LAMM experiment. Meanwhile, the analyses of cutting force and tool wear as an evidence in conjunction with the laser heating application to reduce the materials strength were performed.

Dynamic Analysis of Micro-Milling Machine

Dynamic analysis is very important in developing machine structure to sustain the required accuracy, reliability and productivity. The objective of this study is to conduct a dynamic and modal analyses of micro-milling machine. The machine designs were predicted by comparing the Finite Element Analysis (FEA) using ANSYS software and experimental hammer testing. Two micro-milling machine designs have been proposed. Natural frequency and mode shape was analyzed in modal analysis which show the result that first mode recorded frequency of 92.086 Hz for design A and 154.78 Hz for design B. Natural frequency of design B was higher than design A. From the comparision, it can be concluded that Design B was selected as a best design.