The quality of workpiece surface in rough machining of materials with different hardness values by using segmented grinding wheels produced in Vietnam

2016 ◽  
Vol 38 (5) ◽  
pp. 363-367
Author(s):  
T. P. G. Nguyen
Keyword(s):  
Grinding Wheels ◽  
Rough Machining ◽  
Workpiece Surface ◽  
Hardness Values

Effect of the Coolant Lubricant Type and Dress Parameters on CBN Grinding Wheels Performance

2009 ◽  
Vol 76-78 ◽  
pp. 163-168 ◽  
Author(s):  
Taghi Tawakoli ◽  
Abdolreza Rasifard ◽  
Alireza Vesali
Keyword(s):  
Grinding Wheel ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Workpiece Surface ◽  
Vitrified Cbn

The efficiency of using of CBN grinding wheels highly depends on the dressing process as well as on the coolant lubricant used. The Institute of Grinding and Precision Technology (KSF) investigated the performance of vitrified CBN grinding wheels -being dressed using different parameters- while using two different grinding oils and two different water-miscible coolant lubricants. The obtained results show that the performance of the vitrified CBN grinding wheels regarding the quality of the workpiece surface, the grinding forces as well as the wear of the grinding wheel, highly depend on the dressing conditions and the type of the coolant lubricant used. Compared to the water-miscible coolant lubricants, the grinding oils show better results.

Effects of Ultrasonic Assisted Grinding on CBN Grinding Wheels Performance

2009 ◽  
Author(s):  
Taghi Tawakoli ◽  
Bahman Azarhoushang
Keyword(s):  
Ultrasonic Vibration ◽  
Specific Energy ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Grinding Forces ◽  
Workpiece Surface ◽  
Ultrasonic Assisted Grinding ◽  
Ultrasonic Assisted ◽  
Vitrified Cbn

The effects of ultrasonic assisted grinding on vitrified CBN grinding wheels performance have been investigated. The ultrasonic vibration has been superimposed to the workpiece in feed and cross feed directions and the kinematics of the process in both directions have been discussed. The obtained results show that applying ultrasonic vibration to the grinding process can improve the quality of the workpiece surface, the efficiency of the process and decrease the grinding forces and specific energy considerably.

New Active Online Balancing Method for Grinding Wheel Using Liquid Injection and Free Dripping

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Xining Zhang ◽  
Xu Liu ◽  
Huan Zhao
Keyword(s):  
Grinding Wheel ◽  
Time Varying ◽  
Residual Liquid ◽  
Grinding Wheels ◽  
Abrasive Particles ◽  
Balance Condition ◽  
Liquid Injection ◽  
Grinding Machines ◽  
The Relationship

Grinding is a vital method in machining techniques and an effective way to process materials such as hardened steels and silicon wafers. However, as the running time increases, the unbalance of grinding wheels produce a severe vibration and noise of grinding machines because of the uneven shedding of abrasive particles and the uneven adsorption of coolant, which has a severe and direct impact on the accuracy and quality of parts. Online balancing is an important and necessary technique to reduce the unbalance causing by these factors and adjust the time-varying balance condition of the grinding wheel. A new active online balancing method using liquid injection and free dripping is proposed in this paper. The proposed online balancing method possesses a continuous balancing ability and the problem of losing balancing ability for the active online balancing method using liquid injection is solved effectively because some chambers are full of liquid. The residual liquid contained in the balancing chambers is utilized as a compensation mass for reducing rotor unbalance, where the rotor phase is proposed herein as a target for determining the machine unbalance. A new balancing device with a controllable injection and free dripping structure is successfully designed. The relationship between the mass of liquid in the balancing chamber and the centrifugal force produced by liquid is identified. The performance of the proposed method is verified by the balancing experiments and the results of these experiments show that the vibration of unbalance response is reduced by 87.3% at 2700 r/min.

scholarly journals THE EFFECT OF ABRASIVE GRAIN SHAPES ON QUALITY OF FERRITE MAGNETS GRINDING PROCESS

2020 ◽  
Vol 14 (2) ◽  
pp. 117-124
Author(s):  
Bayu Rahmat Saputro ◽  
Amin Suhadi
Keyword(s):  
Chemical Composition ◽  
Single Layer ◽  
Processing Parameters ◽  
Grinding Process ◽  
Model Design ◽  
Grinding Wheels ◽  
Abrasive Grains ◽  
Abrasive Grain ◽  
Shape And Size

Abstract A research was conducted on the grinding process of ferrite magnet with Strontium ferrite type (SrO.6 (Fe2O3)) using electroplated single layer grinding wheels. Many cracks have been found on work pieces during this work, which is coming from grinding processes. Research is conducted starting from chemical composition test and the effect of the shape and size of the abrasive grain of grinding wheels to the quality of grinding process results by measuring crack ratio of the work piece.  In this experiment, 3 (three) model design of grinding wheels with three different size and shape of abrasive grains are made. All of processing parameters are set at the same value as ordinary process.  The experimental results shown that 3rd model have the best results from the outputs number and also the lowest reject crack ratio compared to 1st and 2nd models. This is because the 3rd model has blocky shape which its distribution structure is denser and more uniform compared to the irregular shape, so that continuous grinding on hard and brittle work pieces is more stable and suitable

Time Molding in Rough Milling of Circular Cavity

2012 ◽  
Vol 723 ◽  
pp. 87-93
Author(s):  
Xiao Ping Ren ◽  
Zhan Qiang Liu ◽  
Yi Wan
Keyword(s):  
High Speed ◽  
Manufacturing Industry ◽  
Cutting Speed ◽  
Circular Cavity ◽  
Rough Machining ◽  
Machining Time ◽  
Workpiece Surface ◽  
High Productivity ◽  
Radial Depth ◽  
Rough Milling

Numerical controlled milling is widely used in the manufacturing industry because of its high productivity and workpiece surface quality. The aim of this work is to establish a methodology to evaluate the rough machining time and to predict optimal values of cutting speed to minimise machining time of circular cavity, during high speed milling. The circular cavity is divided into volumes distributed according to the real radial depth. The obtained results show that the proposed method is consistent with the actual situation.

scholarly journals Modeling of Tool Wear in Vibration Assisted Nano Impact-Machining by Loose Abrasives

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Sagil James ◽  
Murali M. Sundaram
Keyword(s):  
Wear Rate ◽  
Tool Wear ◽  
Experimental Studies ◽  
Tool Wear Rate ◽  
Nanoscale Material ◽  
Workpiece Surface ◽  
Atomic Force ◽  
Hard And Brittle Materials ◽  
Afm Probe

Vibration assisted nano impact-machining by loose abrasives (VANILA) is a novel nanomachining process that combines the principles of vibration assisted abrasive machining and tip-based nanomachining, to perform target specific nanoabrasive machining of hard and brittle materials. An atomic force microscope (AFM) is used as a platform in this process wherein nanoabrasives, injected in slurry between the workpiece and the vibrating AFM probe which is the tool, impact the workpiece and cause nanoscale material removal. The VANILA process are conducted such that the tool tip does not directly contact the workpiece. The level of precision and quality of the machined features in a nanomachining process is contingent on the tool wear which is inevitable. Initial experimental studies have demonstrated reduced tool wear in the VANILA process as compared to indentation process in which the tool directly contacts the workpiece surface. In this study, the tool wear rate during the VANILA process is analytically modeled considering impacts of abrasive grains on the tool tip surface. Experiments are conducted using several tools in order to validate the predictions of the theoretical model. It is seen that the model is capable of accurately predicting the tool wear rate within 10% deviation.

Research of Grinding Material Tools by Modern Grinding Wheels

2013 ◽  
Vol 581 ◽  
pp. 211-216 ◽  
Author(s):  
Jiří Čop ◽  
Imrich Lukovics
Keyword(s):  
Boron Nitride ◽  
Surface Quality ◽  
High Surface ◽  
Cubic Boron Nitride ◽  
High Accuracy ◽  
Grinding Wheels ◽  
Cutting Depth ◽  
High Surface Quality ◽  
Materials Used

This research paper focuses on grinding of materials used for tools (100Cr6 (CSN 4 14109), X210Cr12 ( CSN 4 19436) and epoxy resin) using grinding wheels from cubic boron nitride and diamond. The disadvantage of grinding of difficult-to-machine materials is higher wear of grinding wheels. The modern grinding wheels are able to achieve high accuracy of dimensions and high surface quality with a smaller wear of grinding wheels then grinding wheels from conventional materials. Correctly selected technological conditions are one of the most important matters to achieve the required surface quality. The main aim of this research is to determine the influence of technological conditions to quality of surface after planar grinding. The research determines the influence of the grain type of grinding wheels, feed rate and cutting depth on the quality of functional surfaces.

The Wear of Grinding Wheels: Part 1—Attritious Wear

1971 ◽  
Vol 93 (4) ◽  
pp. 1120-1128 ◽  
Author(s):  
S. Malkin ◽  
N. H. Cook
Keyword(s):  
Surface Finish ◽  
Grinding Force ◽  
Grinding Wheels ◽  
Precision Grinding ◽  
Grinding Forces ◽  
Workpiece Surface ◽  
Abrasive Grain ◽  
The Subject ◽  
Force Components ◽  
Sliding Force

An investigation of attritious and fracture wear of grinding wheels in precision grinding is described in a two paper sequence. Attritious wear, the subject of this first paper, refers to the dulling of the abrasive grain due to rubbing against the workpiece surface. The amount of dulling, measured by the area of the wear flats on the surface of the wheel, is found to be directly related to the grinding forces. In general, both the vertical and horizontal grinding force components increase linearly with the wear flat area. This is explained by considering the grinding force as the sum of a cutting force due to chip formation and a sliding force due to rubbing between the wear flats and workpiece. Related studies of wheel dressing, surface finish, and workpiece burn are also presented.

The Formation and Behaviour of Residual Stresses with Finished Surfaces

2016 ◽  
Vol 686 ◽  
pp. 63-67
Author(s):  
Frantisek Holešovsky ◽  
Radek Lattner ◽  
Martin Novák ◽  
Milan Dian
Keyword(s):  
Residual Stress ◽  
High Pressures ◽  
Load Capacity ◽  
Ground Surface ◽  
Plastic Deformations ◽  
Workpiece Surface ◽  
Dimension Stability ◽  
Machine Parts ◽  
Stress Influences

The single tool grains affect the workpiece surface during grinding in the separated areas of deformation. The elastic and consequently plastic deformations occur at the engagement of grains. The friction of grain and material likewise the friction of elementary chip and grain acts simultaneously. These phenomena are accompanied with an origination of great amount of heat and high pressures and that is the reason for residual stress origin and formation in the ground surface. The residual stress is an important factor in influencing usable properties of machine parts. The stress influences not only the dynamical load capacity of surface but the durability and quality of design units as well. This stress is considered as the source of so called technological notches, having an influence on corrosion resistance, wear resistance, and dimension stability of machine parts.

Tribological Behavior of Different Tool Steels and Surface Properties under Hot Stamping Conditions

2018 ◽  
Vol 767 ◽  
pp. 212-219 ◽  
Author(s):  
Patrik Schwingenschlögl ◽  
Jennifer Tenner ◽  
Marion Merklein
Keyword(s):  
Tribological Behavior ◽  
Hot Stamping ◽  
Manganese Steel ◽  
Pvd Coatings ◽  
Tool Steels ◽  
Forming Process ◽  
Workpiece Surface ◽  
Part Quality ◽  
Strip Drawing

Hot stamping is a well-established technology for producing safety relevant components. The use of hot stamped components in modern car bodies offers the possibility of improving the crash performance while reducing the fuel consumption by using thinner sheet thicknesses. Hot stamped components are mainly produced out of the boron-manganese-steel 22MnB5. To avoid oxide scale formation during the heat treatment and the subsequent forming process AlSi coatings are applied on the workpiece surface. Due to the high forming temperatures, the use of lubricants is not suitable for the hot stamping process. Consequently, high friction and severe wear occur during the forming process and affect the resulting quality of hot stamped parts as well as the tool wear. In order to improve the part quality and increase the efficiency of industrial hot stamping applications, measures for reducing the tribological load during the forming have to be found. Within this study, the tool-sided impact on the tribological conditions is analyzed. Three different hot working tool steels were characterized based on strip drawing experiments under hot stamping conditions. Based on these investigations the tool steel characteristics hardness, thermal conductivity as well as chemical composition have been identified as possible influencing factors on the tribological conditions. Furthermore, the influence of the surface finish on the tribological performance was investigated by analyzing tool surfaces with three different roughness values and two PVD coatings. The experiments indicate a significant reduction of friction and wear due to application of PVD coatings while the tool roughness did not affect the tribological behavior under hot stamping conditions.

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