Design and Experimental Study of the Rolling Enhanced Acoustic System for Gear Tooth Surface

Parameters of gear flanks, such as roughness, hardness, and residual stress, impact their working performance. Therefore, it is essential to optimize these parameters for increasing gears’ life. Thus, this study combined the meshing theory and the ultrasonic surface rolling technology, and presented an innovative design to realize ultrasonic burnishing. First，the dimensions of the ultrasonic burnishing device with two nodes integrated with a gear at the bottom were calculated using frequency equations by a numerical method. Second the correctness of the calculating results was verified by simulations and experiments. Third, the influence of the ratio between the width and diameter of the gear on the acoustic system was studied. Finally, experimental platform of the rolling enhanced acoustic system for gear tooth surface is built successfully. A series of experiments were conducted, and the results showed that the roughness decreased and the hardness and the residual stress improved. Therefore, this design provided a new theory and technology to machine complicated surfaces such as gear flanks.

Improving the X-ray Shielding Performance of Tungsten Thin-Film Plates Manufactured Using the Rolling Technology

X-ray shields used for medical purposes are manufactured using lead, which is inexpensive and easy to manufacture. However, as lead can be a major factor contributing toward environmental contamination, such as lead poisoning, a radiation-shielding plate was manufactured in this study using a tungsten plate, an eco-friendly material, through a rolling process at different temperatures. In addition, the shielding plate produced via the hot-rolling method exhibited better shielding performance than that of the plate produced using the cold-rolling method, and the multilayer structure was well formed, as indicated in the cross-sectional image analysis. Upon applying a peak voltage of 100 kVp to the X-ray tube, the shielding performance observed was 80% and 96% when the plate thickness was 0.1 mm and 0.3 mm, respectively. Therefore, it is expected that, in the future, the pure tungsten-based shield presented in this study will replace lead plates, owing to its superior standardization and reproducibility of the shielding performance.

THREAD ROLLING REPAIR METHOD FOR 3D PRINTED BOLTS

Within this paper, a new method for the quality refinement of external metric standard threads on 3Dprinted bolts is presented. The repair method is based on the application of thread rolling technology, which is applied in terms of cold forming after the regular printing has been finished. The explorative study proves, that the investigated technology has a good potential to solve known precision issues in FDM 3D printing regarding the required accuracy for function fulfilling standardized threads. The application of thread rolling can be done manually and with minimal tool effort, which makes the technology particularly attractive for low cost applications.

Angular Rolling of the Hollow Flanges of Pipe Joints

The paper considers a three-stage technology for angular rolling of the pipe workpiece. This technology facilitates the expansion of the range of flange parts available by eliminating a number of drawbacks of the known methods of metal forming. In the presented paper, we analyze the results of numerical calculations and experiments, as well as the effective deformation values in blank material, using computer simulation in the DEFORM-3D software package. The results of the computer simulation were reached taking into account experimental studies of the rheological properties of copper alloy L68 in the form of a strain hardening curve using the Instron-8850 complex. The results of the ratio of basic geometric dimensions expanded the range of flange parts under investigation and allowed us to consider angular rolling technology with a variable angle of inclination of the rolling roll from a three-stage perspective, especially in small-scale production.

An Experimental Study of the Thermal State of a Steel Billet during Hot Rolling

The technology of hot flat rolling is a complex technological process that includes multiple shaping of a steel billet, the temperature of a bullet ranging from 1100 to 900 degrees [1-6]. To deform a workpiece, mill rolls are used. The control over a workpiece thermal state is an important task aimed at the quality of its manufacturing [7-13]. To achieve the goal, a mathematical model is developed for calculating a steel billet thermal state. The model makes it possible to determine a temperature distribution along the whole length of a workpiece. The study results are useful for researchers and developers of the hot rolling technology, and they can be applied in the organization of the rolling process with an allowance for the temperature distribution. Based on the results, the parameters of steel billet production can be adjusted or changed [14-18].