Using Chatter Vibrations in Milling to Create Tribo-Functional Surfaces for Sheet-Bulk Metal Forming Tools

2013 ◽  
Vol 769 ◽  
pp. 263-270 ◽  
Author(s):  
Rouven Hense

The studies presented in this paper show a concept for setting up a milling process with intentionally invoked chatter vibrations. The process is used for the generation of surface structures on forming tools. Wear of the milling tool is investigated as well as the tribological characteristics of the surfaces. The results lead to the conclusion that this method is suitable for machining challenging materials like high speed steel.

2021 ◽  
Vol 42 (2) ◽  
pp. 124-129
Author(s):  
D. Kazlauskas ◽  
G. Keturakis ◽  
V. Jankauskas ◽  
A. Andriušis

Author(s):  
Xiaohong Lu ◽  
Zhenyuan Jia ◽  
Shengqian Liu ◽  
Kun Yang ◽  
Yixuan Feng ◽  
...  

Abstract In the micro-milling process, the minimization of tool chatter is critical for good surface finish quality. The analysis of chatter requires an understanding of the milling tool as well as the dynamics of milling system structure. Frequency response function (FRF) at the micro-milling tool point reflects dynamic behavior of the whole micro-milling machine–spindle–tool system. However, the tool point FRF of micro-milling cannot be obtained directly through the hammering test. To solve the problem, the authors get the FRF of the spindle system based on the rotating Timoshenko beam theory and the receptance coupling substructure analysis (RCSA), and the bearing characteristics are added into the spindle model through structural modification. Then, the centrifugal force and gyroscopic effect caused by the high-speed rotation of the micro-milling spindle are considered to better simulate the real scenario and increase the accuracy of modal parameters. The method has general usage and can be applied to all the micro-milling tools under which only the spindle dimension, bearing characteristics, and contact parameters need to be changed.


2011 ◽  
Vol 473 ◽  
pp. 91-98 ◽  
Author(s):  
Marion Merklein ◽  
A. Erman Tekkaya ◽  
Alexander Brosius ◽  
Simon Opel ◽  
Lukas Kwiatkowski ◽  
...  

The demand on closely-tolerated and complex functional components in the automotive sector, like e.g. synchronizer rings, leads to the development of a new process-class named “sheet-bulk metal forming”. Within this technology bulk metal forming operations are applied on sheet metals. In the following two novel approaches considering machines and tools for sheet-bulk metal forming are presented. The first approach aims on a technology based on rolling, which is suitable for mass production. The second one is an incremental forming solution for low batch production. Both machine concepts allow the application of different forming strategies to manufacture individual tailored semi-finished products in term of a pre-distribution of material. These products feature variable sheet thicknesses and mechanical properties, which can be adapted to their case of applica-tion. Depending on the individual batch size, the blanks can be finished to functional parts by sub-sequent forming processes like deep drawing and upsetting, extrusion or incremental forming. In this paper the case of an incremental tooth-forming is mainly considered. Forming sequences and resulting loads are modeled and calculated by finite elements simulations for all discussed processes to serve as a basis for the design and dimensioning of the machine components and forming tools.


Author(s):  
Josiah A. Bryan ◽  
Roger C. Fales

Various models have been proposed to estimate the undeformed thickness of chips produced by a CNC milling tool, in order to calculate the forces acting on the tool. The choice of model significantly affects the simulated dynamics of the tool, thereby affecting the dynamic stability of the simulated process and whether or not chatter occurs in a given cutting scenario. Simulations of the dynamics of the milling process can be used to determine the conditions at which chatter occurs, which can lead to poor surface finish and tool damage. The dynamics of a traditional model and a more detailed numerical model are simulated here with particular emphasis on the differences in their chatter bifurcation points. High-speed, low-radial-immersion milling processes are simulated because of their application in industrial high-precision machining.


2016 ◽  
Vol 10 (1) ◽  
pp. 37-50 ◽  
Author(s):  
Petra Kersting ◽  
Daniel Gröbel ◽  
Marion Merklein ◽  
Peter Sieczkarek ◽  
Sebastian Wernicke ◽  
...  

2014 ◽  
Vol 657 ◽  
pp. 88-92
Author(s):  
Traian Grămescu ◽  
Constantin Cărăușu

In the laboratory of cutting machining technologies from the “Gheorghe Asachi” Technical University of Iaşi, a series of investigations on the machinability of cast iron samples having various structures were designed and developed. The aim of the research was to know and to explain the way in which various constituents of some iron castings exert influence on the degree of wear of a milling tool made of high speed steel. Within this research, mathematical empirical models were determined, in order to calculate the cutting speed v60, considered as an indicator for the evaluation of machinability. The research allowed establishing the factors able to have a major influence on tool wear phenomenon and obtaining thus a more complete image concerning the machinability of grey iron used for castings.


2018 ◽  
Vol 53 (3) ◽  
pp. 191-198
Author(s):  
Jakeer Hussain Shaik ◽  
K Ramakotaiah

Analysis of chatter stability in an end milling process is quite cumbersome because of the inaccurate knowledge in the spindle’s geometrical design, position of the bearings and several issues related to the spindle structure. The effective position of bearings of the spindle plays a key role in investigating the self-excited chatter vibrations, which requires an accurate transfer function at the most flexibility region of the spindle tool structure. The present work focuses on the development of a novel method of measuring the spindle vibration responses experimentally using sine sweep tests for a CNC end milling machine tool. Using these model data, an analytical model of the spindle is estimated by considering the bearing span as a design variable. Trial runs are conducted until the convergence between the identified transfer function from the model and that from experiment is achieved. The final model of the spindle system is then applied with time-varying cutting forces so as to obtain the process stability.Bangladesh J. Sci. Ind. Res.53(3), 191-198, 2018


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