Study on the Effect of Removing the Slide Wire Screw on Locking Plate by Nail Groove Reconstruction Method

Background: This paper is to describe and evaluate the nail groove reconstruction method in removing slide wire screw on locking plate. Then compare the method with tungsten steel drilling nail method, to explore a new method of removing slide wire screw on locking plate.Method: A total of 1254 patients with removal fracture internal fixation devices were collected from the Affiliated Hospital of Hangzhou Normal University from July 2015 to September 2021, of which 62 cases met the inclusion and exclusion criteria. All patients were randomly divided into the experimental group and the control group. 31 people per group. There were 19 males and 12 females in the experimental group, the age of patients was 35.68±11.70years; while 18 males and 13 females in the control group, the age of patients was 36.27±10.37years. Nail groove reconstruction method was used in the experimental group, and the tungsten steel drilling nail method was used in the control group. Collect and count surgical-related indicators, the data of two groups were compared and analyzed from four aspects: intraoperative blood loss, operation time, incision healing time and limb function recovery time.Result: All slide wire screws were removed successfully, and all patients had no serious postoperative complications such as internal fixation retention and neurovascular injury. The experimental group was better than the control group in the following three aspects: the amount of intraoperative blood loss, the operative time, the recovery time of limb function, and the differences were statistically significant(p < 0.05). There was no significant difference in incision healing time between the two groups.Conclusion: The nail groove reconstruction method has less damage to the bone and soft tissue, less intraoperative blood loss, shorter operation time, and faster postoperative recovery of limb function. The nail groove reconstruction method is a simple and effective method, it has obvious advantages compared with the traditional method.

Experimental Study on the Influence of Tool Electrode Material on Electrochemical Micromachining of 304 Stainless Steel

Different cathode materials have different surface chemical components and machining capacities, which may finally result in different machining quality and machining efficiency of workpieces. In this paper, in order to investigate the influence of cathode materials on the electrochemical machining of thin-walled workpiece made of 304 stainless steel, five cylindrical electrodes are used as the target working cathodes of electrochemical machining to conduct experiments and research, including 45# steel, 304 stainless steel, aluminum alloy 6061, brass H62, and tungsten steel YK15. The stray current corrosion, taper, and material removal rate were used as the criteria to evaluate the drilling quality of efficiency of a thin-walled workpiece made of 304 stainless steel. The research results show that from the perspectives of stray current corrosion and taper, aluminum alloy 6061 is an optimal tool cathode, which should be used in the electrochemical machining of thin-walled workpieces made of 304 stainless steel; on the aspect of material removal rate, the 45# steel, 304 stainless steel, and aluminum alloy 6061 present close material removal rates, all of which are higher than that of brass H62 and tungsten steel YK15. Based on comprehensive consideration of both machining quality and machining efficiency, the aluminum alloy 6061 is the best option as the cathode tool in the electrochemical machining of thin-walled workpieces made of 304 stainless steel.

Overview of the Mechanical Properties of Tungsten/Steel Brazed Joints for the DEMO Fusion Reactor

A Demonstration (DEMO) thermonuclear reactor is the next step after the International Thermonuclear Experimental Reactor (ITER). Designs for a DEMO divertor and the First Wall require the joining of tungsten to steel; this is a difficult task, however, because of the metals’ physical properties and necessary operating conditions. Brazing is a prospective technology that could be used to solve this problem. This work examines a state-of-the-art solution to the problem of joining tungsten to steel by brazing, in order to summarize best practices, identify shortcomings, and clarify mechanical property requirements. Here, we outline the ways in which brazing technology can be developed to join tungsten to steel for use in a DEMO application.

Improving the precision of micro-EDM for blind holes in titanium alloy by fixed reference axial compensation

During the electrical discharge machining (EDM) process, the tool electrode wear is inevitable, which affects the process precision of the micro-hole. In the present experimental investigation, a fixed reference axial compensation (FRAC) method is proposed to enhance the machining precision of micro-hole. The effect of pulse power, compensation methods, and electrode materials on the depth and roundness factor of micro-hole are explored. The experiment results show that the FRAC method can realize the accurate compensation and reach the expected depth hole processing. When the FRAC is used, the depth deviation is less than 0.43%, and the minimum difference from the expected depth is only 0.106 µm. In addition, the micro-holes of tungsten steel and brass electrodes machine by the FRAC method were close to the expected depth, the difference from the expected depth less than 0.7%, but the bottom of micro-hole produced a cone. However, compared to tungsten steel and brass electrodes, the copper electrode has a better processing performance, the roundness factor is up to 79.8%. When the long-pulse power supply is applied, the expected depth of 400–1,600 µm blind holes with a better processing shape, and the phenomenon of the cone at the bottom are not apparent. Therefore, the proposed FRAC method can be utilized in many high-end manufacturing fields to improve the precision of the micro-hole for micro features.