International Journal of Abrasive Technology (5 papers in press)

Regular Issues

• An Experimental Study on the Prediction of Grinding Wheel Dressing Intervals by Relating Wheel Loading and Surface Roughness  
  by VIPIN GOPAN, Leo Dev Wins K, Arun Surendran 
  Abstract: Grinding being the most commonly performed finishing process and requires frequent dressing operation to restore the original cutting capability of the abrasive wheel. Predicting the time to carry out the dressing operation is very significant in grinding process. The present work focuses on predicting the dressing intervals based on the final surface finish. The surface finish was primarily affected by the wheel parameters, grinding parameters and wheel loading. Wheel parameters were kept constant in this research work and grinding parameters were optimized using Artificial Neural Network-Particle Swarm Optimization (ANN-PSO) approach. Since the grinding parameters were optimized, now the surface roughness depends primarily on wheel loading. Experiments were conducted on cylindrical grinding machine with AISI D2 steel as the work specimen. Wheel loading is quantitatively evaluated by machine vision and image processing technique and surface roughness was monitored during the grinding process. Artificial neural network was used for developing the computational model for correlating the wheel loading and surface roughness data. This developed predictive model was used for determining the dressing intervals based on the surface finish requirement for different applications. Experimental results show that a strong correlation exists between wheel loading and surface roughness which determines the dressing intervals and this correlation can be used an explicit criterion in determining the dressing intervals.
  Keywords: Wheel loading; Artificial neural network; Particle swarm optimization; Image processing; Wheel dressing; Optimization; Condition Monitoring; Machine vision; image segmentation; thresolding; abrasive grains; chip removal.
  
  
• Investigation on Magnetic Polishing Characteristics of Metal Additive Manufactured Ti-6Al-4V  
  by Tatsuya Furuki, Takamasa Hirano, Hiroyuki Kousaka 
  Abstract: The metal additive manufacturing (AM) of Ti6Al4V is expected to fabricate artificial replacement products with high efficiency. A hybrid additive manufacturing machine that combines with a machining center was developed in the recent years. A desired shape can be obtained, but generating a high-accuracy surface roughness is difficult. However, these products need a high surface quality. These products are generally polished by hand work, resulting in the deterioration of the shape accuracy or increase in the non-machining time. Therefore, this study develops a magnetic polishing method that can polish Ti alloy on a hybrid metal AM machine. A workpiece made of Ti6Al4V is fabricated in the metal AM machine, and is ball end-milled to a flat shape. The workpiece is then magnetically polished on the machining center. The pressing force, polished amount, and surface roughness are measured. Moreover, the Preston constant of the additive manufactured Ti6Al4V is calculated. A typical Ti6Al4V is also magnetically polished, with its Preston constant calculated. In summary, the Preston constant of the additive manufactured Ti6Al4V was approximately 0.78 times smaller than that of the typical Ti6Al4V.
  Keywords: magnetic polishing; metal additive manufacturing; machining center; Ti-6Al-4V; Preston constant.
  
  
• Experimental Study on Abrasive Water-jet Polishing of Cemented Carbide and Polycrystalline Diamond (PCD) Tools  
  by Julius Caesar Puoza 
  Abstract: This research paper studies the material removal mechanism, influence of water jet pressure and jet impact angle on the polishing effect of cemented carbide and polycrystalline diamond cutting tool surfaces and edges. A high-pressure nanodiamond abrasive water jet polishing system was built for this experiment to polish the edge of super-hard cutting tools. The results showed that the water jet pressure and jet impact angle have little influence on the surface roughness, but have a great influence on the materials removal efficiency. The jet angle of 15
  Keywords: Polycrystalline diamond tool; cemented carbide tool; water jet polishing; edge strengthening; processing parameters.
  
  
• Research on scan polishing flat surfaces with a small diameter tool  
  by He Wang, Weimin Lin 
  Abstract: High profile accuracy and high surface quality, which are achieved by stable polishing velocity, are needed in the machining of NiP neutron reflection mirror along with suitable machining tools. To respond to the growing demands for high quality reflection mirrors, in this study, a small diameter polishing tool was used on a three-axis CNC ultra-precise polishing machine. Mathematical models of polished profiles based on the Preston equation were built and discussed along with the simulation results of the polished profiles. These models of polished profiles were proved to be effective by numerous experiments under diverse conditions. The polishing characteristics of electro-less plated NiP surface were reviewed, and smooth surfaces could be achieved by scan-type polishing.
  Keywords: NiP; Finishing; Material removal velocity; Polishing models.
  
  
• A Study of methods for the magnetorheological finishing of glass panels for the inner screen of mobile phones  
  by Bin Luo, Qiusheng Yan, Jisheng Pan, Jiabin Lu 
  Abstract: In order to solve the problem that there are many scratches on the glass panels of the inner screen of mobile phones after chemical mechanical polishing (CMP), three different magnetorheological finishing (MRF) methods were investigated to polish the surface: (1) single-point MRF with static magnetic field, (2) cluster MRF with static magnetic fields, and (3) cluster MRF with dynamic magnetic fields, which turned out to be the most suitable one of the three. The rotation of a permanent magnet relative to the polishing disc generates dynamic magnetic fields, which have a positive effect on the polishing process and thus enable an ultra-smooth, scratch-free, high-quality surface on the glass panels required for the inner screen of mobile phones. Single-factor experiments were carried out to further adjust the key process parameters, such as machining time, machining gap, magnetic-pole speed, polishing-disc speed, and workpiece speed. An optimised parameter set of 20 min machining time, 1.0 mm machining gap, 120 r/min magnetic-pole speed, 60 r/min polishing-disc speed, and 400 r/min workpiece speed led to an improvement of the original surface roughness of a glass panel with scratches and pits from Ra 1.15 nm to Ra 0.45 nm, that is tantamount to an ultra-smooth surface.
  Keywords: Magnetorheological finishing; MRF; single-point MRF; cluster MRF; static magnetic field; dynamic magnetic field; glass panel; mobile phone; surface roughness.