Dynamic Analysis and Design of Steel-Ball Grinding Machines Based on No-Slip Cases
Based on no-slip cases between steel balls and lapping discs while a horizontal grinding machine is working, the motion equations of the ball lapping are established and the law of motion is revealed by the MATLAB software. This paper shows that the difference of the trace spacing is reduced by increasing the disc diameter, which can make the trace distribution of the steel ball surface more uniform. In order that balls do not slip when rotary disc drives them to rotate, the ranges of the lapping pressure and lapping disc speed is deduced by using the dynamics analysis considering from the vertical trench surface and along the groove surface, respectively. Finally, this paper takes the selected material as an example to analyze the process parameters that affect the lapping curves, and explains the selection principles of alpha and beta when the trench has some bias, which can provide a reference to improve the quality of the steel balls surface.
Data-based Probe for Bearing Balls using Design Expert with Biodegradable Media
This paper discusses about the lapping process for both metallic and non-metallic materials. The experiments were carried out based on the RSM design of experiments (DOE) approach to investigate the effect of their parameters on the lapping quality of ball bearing, for predicting the new results. This study explored the modification for fine finishing of bearing balls through Biodegradable medium (Aloe Vera) and silicon carbide (SiC) powder as an abrasive in addition of conventional oil-based media having an advantage like Antioxidant, antibacterial, non–toxic, good compression, and shear stresses. Spindle speed (rpm), Time (minutes), Force (N), Abrasive concentration were considered as the input process variables while the PISF, MRR and surface Roundness was considered as the process response. The result shows the most significant parameter for maximum PISF of 82.3%, 7.6 mg/min MRR and 9.05μm roundness was achieved with 672 rpm at 7.5 N force, 37.5% abrasive concentration, 165 minutes experimental run time, was achieved.
Physical Ageing of the Research Reactor Core Structural Materials Due to Neutron Irradiation Exposure: a Review
A research reactor (RR) is a  nuclear reactor that has function to generate and utilize neutron flux and radiation ionization for  research purposes and industrial applications. More than 60% of current operating RRs have  been operated for 30 years or more. As the time passes, the functional capabilities of structures,  systems and components (SSCs) of those RRs deteriorate by physical ageing, which can be  caused by neutron irradiation exposure such as irradiation induced dislocation and  microstructural changes. To extend the lifetime and/or to avoid unplanned outages, ageing on  the safety related SSCs of RRs need to be properly managed. An ageing management is a  strategy to engineer, operate, maintenance, and control SSC degradation within acceptable limits. The purpose of this study is to review physical ageing of the core structural materials of  the RRs caused by neutron irradiation exposure. In order to achieve this objective, a wide range  of literatures are reviewed. Comprehensive discussions on irradiation behaviors are limited only  on reactor vessel and core support structure materials made from zirconium and beryllium as  well as their alloys, which are widely used in RRs. It is found that the stability of the mechanical  properties of zirconium and beryllium as well as their alloys was mostly affected by the neutron  fluences and temperatures.