Application of Measurement Systems in Tool Condition Monitoring of Milling: A Review of measurement science approach

This paper explores the consequences of applying an ultrasonic vibration-assisted ball burnishing process and its non-vibration assisted version on the topology and subsurface microstructure of a transformation-induced plasticity AISI 301LN alloy. More specifically, four different metallographic conditions provided as 1.5-mm thickness sheets and characterized by different starting martensite content (3, 10, 20 and 40 wt.%) are included in the study. Ball burnishing was performed along the lamination direction and perpendicular to it. Results show that the effect of ball burnishing is strongly correlated with the pre-existing microstructure. The steel containing the lowest quantity of initial martensite is the most affected by the process, achieving a higher residual hardening effect, similar to the untreated steel with an original martensitic content of around 40 wt.%. Moreover, the process succeeds in generating a 100-nm thick nanograin layer under the plate subsurface. Finally, no conspicuous effect of the application of vibration assistance was observed, which encourages the application of alternative measurement techniques in future works to define its effect on the properties after being ball burnished.

Superficial Effects of Ball Burnishing on TRIP Steel AISI 301LN Sheets

This contribution reports the effects of an ultrasonic-vibration assisted ball burnishing process on the topological descriptors of nickel-based alloy Udimet®720. This material is of high interest for the transportation industry, and specifically for the aeronautical sector. Despite the acknowledged necessity to finish this material to achieve excelling mechanical performances of parts, surface integrity enhancement by means of plastic deformation through ball burnishing has seldom been explored in previous references so far. In this paper, different surface descriptors are used to report how the topology changes after ultrasonic-assisted ball burnishing, and how burnishing conditions influence that change. The burnishing preload and the number of passes are the only influential factors on surface change, whereas the feed velocity of the tool and the strategy reveal not to be relevant on the result. Additionally, the extent to which the process successfully modifies the objective surfaces is highly divergent depending on the original scale of the treated surface. The assistance of the process with vibrations also shows that the resulting topologies are characterized by a periodical pattern of repetitive peaks and valleys that are extended on the surface with a higher frequency in comparison to the non-assisted process, which could influence in the functional deployment of workpieces treated through it, and could deliver an advantage with regard to its non-assisted homologous process.

Enhancing surface topology of Udimet®720 superalloy through ultrasonic vibration-assisted ball burnishing

Structural control and health monitoring as condition monitoring are some essential areas that allow for different system parameters to be designed, supervised, controlled, and evaluated during the system’s operation in different processes, such as those used in machinery, structures, and different physical variables in mechanical, chemical, electrical, aeronautical, civil, electronics, mechatronics, and agricultural engineering applications, among others [...]

Sensors for Structural Health Monitoring and Condition Monitoring.

The superficial effect of hardening caused after vibration-assisted ball burnishing and its consequences in the tensile behavior of a carbon steel material are studied in this paper. As ball burnishing affects the material to hundredths of micrometers in depth through plastic deformation, the overall macro effect of this modification was studied. Different levels of preload and vibration amplitude were studied to address the described issue. The study was done in two phases. First of all, the depth to which ball burnishing affects the material was studied by performing Vickers indentation tests with different loads. It was proven that the effects of ball burnishing are best represented when a 0.05 kg load is used, as higher loads include more volume of core material in the measurement, hence hiding the effect of ball burnishing. In a second phase, the ball burnished specimens were subjected to tensile tests. It was proven that an increase of burnishing preload diminishes the ductile behavior of the material and increases its strength representative values, although the proportion of affected material in the cross-section of the specimen is reduced with regard to the whole surface. Additionally, as the preload increases, the effects of assistance through vibrations is reduced, and the effect of the static preload acquires more relevance in modifying the macroscopic mechanical properties of the steel alloy. Experiments using different amplitudes and new forces are encouraged to obtain more information about how the material can be modified optimally through vibration-assisted ball burnishing.

Mechanical Strengthening in S235JR Steel Sheets through Vibration-Assisted Ball Burnishing

Ball burnishing is a superfinishing operation whose objective is the enhancement of surface integrity of previously machined surfaces, hence its appropriateness to complement chip removal processes at the end of a production line. As a complex process involving plastic deformation, friction and three-dimensional interaction between solids, numerical solutions and finite element models have typically included a considerable amount of simplifications that represent the process partially. The aim of this paper is to develop a 3D numerical finite element model of the ball burnishing process including in the target workpiece real surface integrity descriptors resulting from a ball-end milled AISI 1038 surface. Specifically, its periodical topological features are used to generate the surface geometry and the residual stress tensor measured on a real workpiece is embedded in the target surface. Secondly, different models varying the effect of the coefficient of friction and the direction of application of burnishing passes with regards to the original milling direction are calculated. Results show that the resulting topology and residual stresses are independent of the burnishing direction. However, it is evident that the model outputs are highly influenced by the value of the coefficient of friction. A value of 0.15 should be implemented in order to obtain representative results through finite element models.

https://www.mdpi.com/2075-4701/10/5/638/pdf

Finite Element Analysis of Ball Burnishing on Ball-End Milled Surfaces Considering Their Original Topology and Residual Stress

Although numerous references present the beneficial effects on surface integrity of ultrasonic vibration-assisted ball burnishing (UVABB), nothing has been reported about the dynamic behavior of the UVABB tool, workpiece, and machine triad during the process. In this paper, a dynamic monitorization through a set of 5 accelerometers is tested to analyze the interactions between the tool–workpiece–machine mechanical assembly. A UVABB tool attached to a milling machine and equipped with a piezoelectric stack that is able to assist the process with a 40-kHz vibration is tested on a milled C45 steel surface. First, the natural frequencies of the mechanical system are obtained through hammer impact tests. Then, the vibratory signals transmitted during the execution of the process are monitored and compared to those: two feed velocities and two burnishing preloads, all with and without vibration-assistance. Results show that the proposed accelerometer set is valid to assess the behavior of a UVABB process. The system’s natural frequencies are not varied by vibration-assistance and are not excited when the piezoelectric is functioning. It is confirmed that UVABB is safe for the machine and the tool, and there is no unexpected excited frequencies due to the piezoelectric excitation.

https://www.mdpi.com/1424-8220/20/9/2562/pdf

Monitoring of Processing Conditions of an Ultrasonic Vibration-Assisted Ball-Burnishing Process.

This paper focuses on a resonant system used to induce a low-amplitude movement and ultrasonic frequency to complement a ball burnishing process on a lathe. The system was characterized through the combination of different techniques. A full vibratory characterization of this process was undertaken with the purpose of demonstrating that the mechanical system—composed of the tool and the machine—does not present resonance phenomena during the execution of the operation that could lead to eventual failure. This dynamic analysis validates the adequateness of the tool when attached to an NC lathe, which is important to guarantee its future implementation in actual manufacturing contexts. A further aim was to confirm that the system succeeds in transmitting an oscillating signal throughout the material lattice. To this end, different static and dynamic techniques that measure different vibration ranges—including impact tests, acoustic emission measurement, and vibration measurement—were combined. An operational deflection shape model was also constructed. Results demonstrate that the only high frequency appearing in the process originated in the tool. The process was not affected by the presence of vibration assistance, nor by the burnishing preload or feed levels. Furthermore, the frequency of the assisting ultrasonic vibration was characterized and no signal due to possible damage in the material of the specimens was detected. These results demonstrate the suitability of the new tool in the vibration-assisted ball burnishing process.

Aida Estevez-Urra

Papers

Finite Element Analysis of Ball Burnishing on Ball-End Milled Surfaces Considering Their Original Topology and Residual Stress

Monitoring of Processing Conditions of an Ultrasonic Vibration-Assisted Ball-Burnishing Process.

Ultrasonic Vibration-Assisted Ball Burnishing Tool for a Lathe Characterized by Acoustic Emission and Vibratory Measurements.