A Compound Vibratory Mode in High Speed Vibratory Tapping

2009 ◽  
Vol 69-70 ◽  
pp. 379-383 ◽  
Author(s):  
L. Wang ◽  
Gui Cheng Wang ◽  
J.H. Zhu ◽  
Hong Jie Pei ◽  
L.F. Lin

Based on the investigation of two traditional vibratory modes, this paper puts forward a novel vibratory mode in high speed tapping. Vibratory tapping on stainless steel with all kinds of vibratory modes is carefully studied. Experimental results show that the new vibratory mode not only preserves the machining effect of the separable vibratory tapping, but also increases the life of tap. Therefore this study provides a new solution to increase the performance of high speed vibrat- ion tapping.

2009 ◽  
Vol 407-408 ◽  
pp. 619-623
Author(s):  
Shao Fu Huang ◽  
Di Zhu ◽  
Yong Bin Zeng ◽  
Yong Liu ◽  
Wei Wang

In order to remove the reaction products generated from the interelectrode gap of the electrochemical micro-machining, an angle adjustable electrochemical micro-machining equipment has been developed, which consists of angle adjustment unit, feed system unit, etc. Small holes have been drilled on thin stainless steel 304 by using our developed equipment. The experimental results show that the adjusted cathode working angle and high speed of cathode rotation improves micro-ECM performance characteristics.


2012 ◽  
Vol 184-185 ◽  
pp. 684-687 ◽  
Author(s):  
Jun Yi ◽  
Xiao Min Sheng ◽  
Can Bo Feng

Abstract. Embedded K nickel chrome-nickel silicon thermocouple was used to measure the grinding temperature of stainless steel in the cases of high-speed grinding while machining SUS304 Stainless Steel with vitrified CBN wheels in high speed grinding conditions.The energy partition is approximately 7.7% by matching the measured temperature to the analytically computed temperature. 3D FEM simulations for some typical grinding conditions are carried out.The error between the simulation analysis temperature results and the experimental results is approximately 3% on the grinding surface,and the error between the simulation analysis temperature results and the experimental results is approximately 10% below the grinding surface.


Alloy Digest ◽  
1992 ◽  
Vol 41 (2) ◽  

Abstract LESCALLOY BG42 VIM-VAR is a martensitic stainless high-speed steel that combines the temper resistance and hot hardness characteristics of M-50 high-speed steel with the corrosion resistance of AISI Type 440C stainless steel. (See also LESCALLOY BG42, Alloy Digest SS-280, October 1972.) This datasheet provides information on composition, physical properties, and elasticity. It also includes information on forming, heat treating, machining, and joining. Filing Code: SS-179. Producer or source: Latrobe Steel Company. Originally published as Lesco BG42, March 1966, revised February 1992. See also Alloy Digest SS-356, October 1978.


Author(s):  
Francisco Lamas ◽  
Miguel A. M. Ramirez ◽  
Antonio Carlos Fernandes

Flow Induced Motions are always an important subject during both design and operational phases of an offshore platform life. These motions could significantly affect the performance of the platform, including its mooring and oil production systems. These kind of analyses are performed using basically two different approaches: experimental tests with reduced models and, more recently, with Computational Fluid Dynamics (CFD) dynamic analysis. The main objective of this work is to present a new approach, based on an analytical methodology using static CFD analyses to estimate the response on yaw motions of a Tension Leg Wellhead Platform on one of the several types of motions that can be classified as flow-induced motions, known as galloping. The first step is to review the equations that govern the yaw motions of an ocean platform when subjected to currents from different angles of attack. The yaw moment coefficients will be obtained using CFD steady-state analysis, on which the yaw moments will be calculated for several angles of attack, placed around the central angle where the analysis is being carried out. Having the force coefficients plotted against the angle values, we can adjust a polynomial curve around each analysis point in order to evaluate the amplitude of the yaw motion using a limit cycle approach. Other properties of the system which are flow-dependent, such as damping and added mass, will also be estimated using CFD. The last part of this work consists in comparing the analytical results with experimental results obtained at the LOC/COPPE-UFRJ laboratory facilities.


2007 ◽  
Vol 340-341 ◽  
pp. 283-288 ◽  
Author(s):  
Jung Han Song ◽  
Hoon Huh

The dynamic response of the turbine blade materials is indispensable for analysis of erosions of turbine blades as a result of impulsive loading associated with gas flow. This paper is concerned with the dynamic material properties of the Inconel 718 alloy which is widely used in the high speed turbine blade. The dynamic response at the corresponding level of the strain rate should be acquired with an adequate experimental technique and apparatus due to the inertia effect and the stress wave propagation. In this paper, the dynamic response of the Inconel 718 at the intermediate strain rate ranged from 1/s to 400/s is obtained from the high speed tensile test and that at the high strain rate above 1000/s is obtained from the split Hopkinson pressure bar test. The effects of the strain rate on the dynamic flow stress, the strain rate sensitivity and the failure elongation are evaluated with the experimental results. Experimental results from both the quasi-static and the high strain rate up to 3000/s are interpolated in order to construct the constitutive relation that should be applied to simulate the dynamic behavior of the turbine blade made of the Inconel 718.


Author(s):  
Mohammad Malekan ◽  
Camilla D. Bloch-Jensen ◽  
Maryam Alizadeh Zolbin ◽  
Klaus B. Ørskov ◽  
Henrik M. Jensen ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1537
Author(s):  
Beata Skowrońska ◽  
Tomasz Chmielewski ◽  
Mariusz Kulczyk ◽  
Jacek Skiba ◽  
Sylwia Przybysz

The paper presents the microstructural investigation of a friction-welded joint made of 316L stainless steel with an ultrafine-grained structure obtained by hydrostatic extrusion (HE). Such a plastically deformed material is characterized by a metastable state of energy equilibrium, increasing, among others, its sensitivity to high temperatures. This feature makes it difficult to weld ultra-fine-grained metals without losing their high mechanical properties. The use of high-speed friction welding and a friction time of <1 s reduced the scale of the weakening of the friction joint in relation to result obtained in conventional rotary friction welding. The study of changes in the microstructure of individual zones of the friction joint was carried out on an optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and electron backscattered diffraction (EBSD) analysis system. The correlation between the microstructure and hardness of the friction joint is also presented. The heat released during the high-speed friction welding initiated the process of dynamic recrystallization (DRX) of single grains in the heat-affected zone (HAZ). The additional occurrence of strong plastic deformations (in HAZ) during flash formation and internal friction (in the friction weld and high-temperature HAZ) contributed to the formation of a highly deformed microstructure with numerous sub-grains. The zones with a microstructure other than the base material were characterized by lower hardness. Due to the complexity of the microstructure and its multifactorial impact on the properties of the friction-welded joint, strength should be the criterion for assessing the properties of the joint.


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