Performance of novel 3D printing tools in removing coronary-artery calcification tissue

Rotational atherectomy is an effective treatment for severe vascular calcification obstruction,and relies on high-speed grinding(typically 130,000–210,000 r/min)with miniature grinding tools to remove calcified tissue and restore blood flow.However,reports of intraoperative complications are common because of the grinding force,temperature,and debris directly acting on the body during the grinding process,which can easily cause damage to patients.In this study,three novel grinding tools were designed and fabricated and a series of experiments have been conducted to analyze the effects of tool geometry and parameters on grinding performance,that is,force,temperature,and specimen surface morphology.The results show that these tools can effectively remove simulated calcified tissue and that they have two motions,rotation and revolution,in the tube.At higher rotational speeds,grinding force and temperature increase noticeably,while the amount of debris decreases significantly.In addition,by observing the surface morphology of the specimens,we concluded that the material removal rate per unit time is influenced by both rotational speed and tool geometry,and that high rotational speed and a rough tool surface can improve the material removal rate efficiently.

Laser conditioning and structuring of grinding tools--a review

The conditioning of grinding tools is one of the most important factors for achieving an optimal grinding process. It influences the grinding forces and temperatures and, therefore, the achievable material removal rate, dimensional accuracy and the surface integrity of the workpiece. Furthermore, the roundness, profile accuracy and the wear of the grinding tools are strongly influenced by the conditioning process. The conditioning process should be matched to the abrasive type and the bonding of the grinding tool. Laser conditioning is a promising unconventional and non-contact method, which is able to condition all kinds of abrasives and bonding types. The main advantages of this novel method are no tool wear, good repeatability and controllability, high precision and a relatively short process time. Additionally, using this method, grinding tools can be micro-structured. This paper reviews the literature on the laser conditioning of grinding tools, covering the associated setups, wheel conditioning and structuring mechanisms, and experimental results. It also discusses the technical barriers that have to be overcome before laser conditioning can be fully integrated into manufacturing.

Development of an oscillating grinding machine tool based on error analysis

Oscillating grinding machine tool is the core equipment when machining crankshaft pin journal,which directly determines the final quality.This paper describes the development of an oscillating grinding machine tool based on error analysis.First,the error analysis of oscillating grinding for crankshaft pin journal is carried out,including the effect on machining accuracy caused by each error and corresponding error sensitivity.The results show that the tracking error of X-axis has the greatest influence on the grinding accuracy of pin journal,thus,the grinding carriage feed system is the critical component of an oscillating grinding machine tool,which should be given priority during the development process.Next,the development of an oscillating grinding machine tool is described.The whole structure is given,and the grinding carriage feed system is emphatically presented involving drive mode and assembly method.Other components of the oscillating grinding machine tool are also introduced.Finally,some grinding experiments are performed on the prototype,and the results show that all workpieces are qualified under different conditions,which verify the performance of the developed oscillating grinding machine tool.