Laser-assisted grinding (LAG), as a potential machining method, is expected to achieve high-efficiency machining without any surface damage or sub-surface damage. However, grinding force tends to ...exert serious impact on the surface damage during LAG process. In this paper, a grinding force predictive model for the LAG process was established, which has taken the combined effects of temperature-dependent mechanical properties of the material, statuses of grit-material micro interaction, and stochastic shapes and random distributions of abrasive grits into consideration. This model also reveals the mechanism for the reduction of grinding force during LAG. In the meantime, the simulative grinding force distributions of workpiece surface with different laser powers were obtained. LAG experiments of zirconia ceramic were carried out to validate this model. It is found that the modelled forces are in good agreement with the measured forces and the error rates can be confined within 12 %. In addition, the effect of grinding parameters on grinding force has been investigated. It is demonstrated that the grinding force can be reduced by a certain percentage ranging from 29.4%–60.1% using the optimal machining parameters. Within a certain threshold, higher laser power can improve the surface integrity and decrease the depth of damage. This work is expected to provide significant guidance for promoting the development of the laser-assisted machining technologies.
Ni‐based superalloy Inconel 718 is renowned owing to its admirable physical and mechanical properties at higher temperatures. Various industries including aerospace and automobile are using this ...superalloy in gas turbines and other components. Meanwhile, the excellent mechanical properties (high strength and hardness) of Inconel 718 cause poor machined surface integrity and machinability, which have always been an interesting task in the machining of superalloys. Countless studies are performed on the machinability of Inconel 718 defining optimal cutting parameters and for the advancement of a better understanding of superalloys’ machining like Inconel 718. Herein, a comprehensive review regarding the machining trends of Inconel 718 is offered and the causes of the various symbolic machining parameters are cited on numerous machinability features concerning the modern literature and the earlier one. The machining characteristics including cutting tool wear, cutting forces, and surface reliability such as microhardness, surface roughness, and residual stresses are reviewed.
Herein, Inconel 718 is found to be an outstanding superalloy due to its excellent properties at elevated temperatures. In spite of wide range of applications, machinability still suffers due to hardness and high strength. The machining characteristics such as tool wear, cutting forces, and surface reliability affect the machinability and are reviewed.
Choosing the optimum cutting parameters is regarded as one of the important energy saving technologies. This paper presents a method for complex optimization of cutting parameters with the objectives ...of energy efficiency and processing time, which integrates Taguchi method, response surface method (RSM) and multi-objective particle swarm optimization algorithm (MOPSO). In this study, specific energy consumption (SEC) is selected to evaluate energy efficiency and the calculation model is introduced firstly. Then the method is described in detail. Taguchi is used to design the experiment, signal-to-noise (S/N) ratio is subsequently employed to analyze the performance of parameters on SEC and processing time, and the significant contributions of parameters can be determined by use of range analysis method. RSM is conducted to develop regression models for the responses based on the experimental data, and the optimal machining parameters for minimizing energy and time are determined through the modified MOPSO algorithm. Finally, four machining parameters schemes with different optimization objectives are compared, and the results show that a trade-off point can be drawn between the low processing time and high energy efficiency.
Machining 42CrMo4 martensite-ferrite dual phase steel is challenging due to its high hardness and it is essential to determine the favorable requirements for the optimum machining condition. The ...ability to alter the martensite quantity in dual phase structure of steel leading to variation in bulk hardness is the motivation for machinability investigation. In heavy duty machining, the determination of tool life and surface roughness at various conditions of machining plays an important role in the manufacturing industry. In the present work, machinability tests are carried out on 42CrMo4 martensite-ferrite dual phase steel to assess the tool life and surface roughness. Speed, feed, and depth of cut are varied in different levels. The tests are carried out as per the full factorial method. A microstructure study is performed to correlate the various mechanical properties with phase morphology. The main objective of this study is to obtain the optimized machining process parameters for the turning operation of 42CrMo4 martensite-ferrite dual phase steel. All cutting tests are carried out under dry conditions using a carbide insert. Microstructure and mechanical property analysis shows an increase in the martensite quantity with the increase in the dual phase processing temperature. From the ANOVA results, it is found that the depth of cut is the major contributing factor to the variation of tool life and surface roughness within the range of values considered for the study. Microstructure analysis revealed the distribution of ferrite and martensite phases evenly. The optimum combination of machining parameters is calculated for obtaining a superior combination of tool life and surface roughness. The 42CrMo4 DPS steel may be used for structural applications with wide variation in the property range.
In the manufacturing field of industrial firms, some materials are hard to cut and do not meet the mechanical operation requirements in conventional and unconventional machining methods due to their ...high mechanical properties which poorer their machinability. The need is ongoing and growing to these materials in important industries, therefore hot machining is considered one of the most advanced methods of machining which help to solve the problem of these materials. This process involves heating the work piece at elevated temperature during or before machining on conventional cutting machine by using various external heating techniques, which soften it and becomes more ductile and this leads to improve the machinability. This paper displays a review on hot machining process and presents its effectiveness for the industrial firm in machining hard-to cut-materials which reflect on cost and productivity in relation to other aspects of machining. The review paper presents a survey on various researches which indicates the effect of variation process parameters in hot machining.
Review of machining metal matrix composites Nicholls, Carl J.; Boswell, Brian; Davies, Ian J. ...
International journal of advanced manufacturing technology,
06/2017, Letnik:
90, Številka:
9-12
Journal Article
Recenzirano
Odprti dostop
Metal matrix composites (MMCs) are materials which have been widely used in the aerospace and automobile industries since the 1980s and have been classified as hard-to-machine materials. During the ...intervening years, only a limited amount of research has been conducted into the cutting action of MMCs. As with traditional materials, it is important to understand the wear mechanisms that contribute to tool wear which reduces tool life. The objective of this research is to evaluate the machinability characteristics for these hard-to-machine material MMCs. This review will also establish the optimum machining parameters vital to maximizing tool life whilst producing parts at the desired quantity and quality.
In the recent years with greater emphasis on the environmental and sustainability aspects of engineering materials, natural fiber reinforced composites (NFRCs) are gaining more importance because of ...their numerous advantages. Several researchers have developed NFRCs using various natural fibers as well as matrix materials. However, real-world applications of NFRCs require some secondary operations in order to complete the assembly of the components or parts. Very few researchers have discussed issues related to the machinability of these NFRCs. In this paper, for the first time, a comprehensive literature review on machining of NFRCs is discussed with focus on drilling operation. The paper also reviews the studies on milling and turning of NFRCs. The distinct feature of this review is that it identifies the factors that affect the quality of the machined feature and provides general recommendations for the selection of process parameters so as to generate better quality holes during drilling. In addition, the review also discusses the challenges that hinder machining of NFRCs which is a significant contribution to the field of NFRCs.
PDF
