On the Development of a Chip Breaker in a Metal-Matrix Polycrystalline Diamond Insert: Finite Element Based Design With ns-Laser Ablation and Machining Verification

2017 ◽  
Vol 5 (3) ◽  
Author(s):  
Ahmed Elkaseer ◽  
Jon Lambarri ◽  
Jon Ander Sarasua ◽  
Itxaso Cascón
Keyword(s):  
Finite Element ◽  
Metal Matrix ◽  
High Surface ◽  
Polycrystalline Diamond ◽  
Superior Performance ◽  
Process Conditions ◽  
Original Design ◽  
Dimensional Error ◽  
Chip Breaker ◽  
High Surface Quality

This paper reports the development of an original design of chip breaker in a metal-matrix polycrystalline diamond (MMPCD) insert brazed into a milling tool. The research entailed finite element (FE) design, laser simulation, laser fabrication, and machining tests. FE analysis was performed to evaluate the effectiveness of different designs of chip breaker, under specified conditions when milling aluminum alloy (Al A356). Then, the ablation performance of an MMPCD workpiece was characterized by ablating single trenches under different conditions. The profiles of the generated trenches were analyzed and fed into a simulation tool to examine the resultant thickness of ablated layers for different process conditions, and to predict the obtainable shape when ablating multilayers. Next, the geometry of the designated chip breaker was sliced into a number of layers to be ablated sequentially. Different ablation scenarios were experimentally investigated to identify the optimum processing conditions. The results showed that an ns laser utilized in a controllable manner successfully produced the necessary three-dimensional feature of an intricate chip breaker with high surface quality (Ra in the submicron range), tight dimensional accuracy (maximum dimensional error was less than 4%), and in an acceptable processing time (≈51 s). Finally, two different inserts brazed in milling tools, with and without the chip breaker, were tested in real milling trials. Superior performance of the insert with chip breaker was demonstrated by the curled chips formed and the significant reduction of obtained surface roughness compared to the surface produced by the insert without chip breaker.

scholarly journals Tailored Chip Breaker Development for Polycrystalline Diamond Inserts: FEM-based Design and Validation

2019 ◽  
Vol 9 (19) ◽  
pp. 4117 ◽  
Author(s):  
Cascón ◽  
Sarasua ◽  
Elkaseer
Keyword(s):  
Surface Quality ◽  
Metal Cutting ◽  
High Surface ◽  
Cutting Tools ◽  
Polycrystalline Diamond ◽  
Critical Issue ◽  
Superior Performance ◽  
Machined Surface ◽  
Chip Breaker ◽  
High Surface Quality

Chip evacuation is a critical issue in metal cutting, especially continuous chips that are generated during the machining of ductile materials. The improper evacuation of these kinds of chips can cause scratching of the machined surface of the workpiece and worsen the resultant surface quality. This scenario can be avoided by using a properly designed chip breaker. Despite their relevance, chip breakers are not in wide-spread use in polycrystalline diamond (PCD) cutting tools. This paper presents a systematic methodology to design chip breakers for PCD turning inserts through finite element modelling. The goal is to evacuate the formed chips from the cutting zone controllably and thus, maintain surface quality. Particularly, different scenarios of the chip formation process and chip curling/evacuation were simulated for different tool designs. Then, the chip breaker was produced by laser ablation. Finally, experimental validation tests were conducted to confirm the ability of this chip breaker to evacuate the chips effectively. The machining results revealed superior performance of the insert with chip breaker in terms of the ability to produce curly chips and high surface quality (Ra = 0.51–0.56 µm) when compared with the insert without chip breaker that produced continuous chips and higher surface roughness (Ra = 0.74–1.61 µm).

scholarly journals Functional Approach to Development of Hybrid Technology of Cutting Diamond Carbides

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
А.F. Salenko ◽  
V.Т. Shchetinin ◽  
G.V. Gabuzian ◽  
V.А. Nikitin ◽  
S.А. Klymenko ◽  
...  
Keyword(s):  
Surface Quality ◽  
High Surface ◽  
Polycrystalline Diamond ◽  
Functional Approach ◽  
Surface Layers ◽  
High Surface Quality ◽  
Cut Quality ◽  
Multilayered Composites ◽  
Approach Method ◽  
Product Part

Background: Modern composite materials have a number of advantages in comparison with the traditionally used ones and allow implementing new methods of processing, which makes the finished product cheaper and makes its use more efficient.Objective: In order to improving the surface quality and productivity taken by A functional approach. Method: A functional approach to the development of cutting technologies for Carbide and Super Hard Multilayered Composites is considered. It allows, by alternating the effects of different nature, to obtain qualitative edges, to lower the residual stresses in the surface layers, and to achieve a high surface quality. The essence of the approach is that the method of impact is determined on the basis of a morphological search of options for the execution of individual surface elements, each of which, combined into a set, uniquely forms the function of the finished product. The cutting is determined by a rational sequence of execution of technological transitions, provided that each harmful intermediate function at the finish stage turns into neutral or complements the required useful function.Results: Examples of figured cutting of plates from polycrystalline diamond-containing materials are given, the results of obtaining qualitative edges are shown.Conclusion: Thanks to the proposed technology based on the use of a functionally oriented approach, the functions of the tool for cutting are divided between the tool itself and the product part. As a result, the processing speed increases more than 3 times, and a high cut quality is achieved.

Surface Morphology Improvement and Repeatable Doping Characterization of 4H-SiC Epitaxy Grown on 4° Off-Axis 4H-SiC Wafers

2009 ◽  
Vol 615-617 ◽  
pp. 423-426 ◽  
Author(s):  
Swapna G. Sunkari ◽  
Hrishikesh Das ◽  
Carl Hoff ◽  
Yaroslav Koshka ◽  
Janna R. B. Casady ◽  
...  
Keyword(s):  
Surface Roughness ◽  
High Surface ◽  
Process Conditions ◽  
Power Devices ◽  
Low Loss ◽  
High Surface Quality ◽  
Non Destructive ◽  
Koh Etching

4H Silicon Carbide (4H-SiC) has a great potential for low-loss power devices due to its superior electrical properties. However, the increase in demand for the power devices requires high quality SiC substrates and epitaxial layers. Mercury probe Capacitance Voltage (Hg CV) measurement is a well known procedure to characterize epi layers grown on SiC substrates, due to its non-destructive technique. However, careful calibration of the tool is very important for repeatable and accurate measurements. Here we present very close repeatability of Hg CV within 2.4% (standard deviation 0.7%), between different Solid State Measurements (SSM) setups compared with Ni Schottky (NiS) CV. In addition to growing uniformly doped epi layers, high surface quality of the epi layer is also needed for improved device performance. Improved process conditions resulted in a smooth epi with a surface roughness Ra 1.2 nm for a 6 µm thick epi layer. Molten Potassium Hydroxide (KOH) etching analysis also revealed a significant correlation between the surface roughness and epi defects.

scholarly journals Functional Approach to Development of Hybrid Technology of Cutting Diamond Carbides

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
А.F. Salenko ◽  
V.Т. Shchetinin ◽  
G.V. Gabuzian ◽  
V.А. Nikitin ◽  
S.А. Klymenko ◽  
...  
Keyword(s):  
Surface Quality ◽  
High Surface ◽  
Polycrystalline Diamond ◽  
Functional Approach ◽  
Surface Layers ◽  
High Surface Quality ◽  
Cut Quality ◽  
Multilayered Composites ◽  
Approach Method ◽  
Product Part

Background: Modern composite materials have a number of advantages in comparison with the traditionally used ones and allow implementing new methods of processing, which makes the finished product cheaper and makes its use more efficient.Objective: In order to improving the surface quality and productivity taken by A functional approach. Method: A functional approach to the development of cutting technologies for Carbide and Super Hard Multilayered Composites is considered. It allows, by alternating the effects of different nature, to obtain qualitative edges, to lower the residual stresses in the surface layers, and to achieve a high surface quality. The essence of the approach is that the method of impact is determined on the basis of a morphological search of options for the execution of individual surface elements, each of which, combined into a set, uniquely forms the function of the finished product. The cutting is determined by a rational sequence of execution of technological transitions, provided that each harmful intermediate function at the finish stage turns into neutral or complements the required useful function.Results: Examples of figured cutting of plates from polycrystalline diamond-containing materials are given, the results of obtaining qualitative edges are shown.Conclusion: Thanks to the proposed technology based on the use of a functionally oriented approach, the functions of the tool for cutting are divided between the tool itself and the product part. As a result, the processing speed increases more than 3 times, and a high cut quality is achieved.

Investigation on Sheet Hydroforming Process of Titanium/Aluminum Clad Metal Housing

2010 ◽  
Author(s):  
Huang-Chi Tseng ◽  
Zong-Chun Wu ◽  
Chinghua Hung ◽  
Ming-Hu Lee
Keyword(s):  
Finite Element ◽  
High Surface ◽  
Dimensional Accuracy ◽  
Drawing Ratio ◽  
Explicit Finite Element ◽  
Sheet Hydroforming ◽  
High Surface Quality ◽  
Titanium Aluminum ◽  
Significant Process ◽  
Hydroforming Process

In this research, the sheet hydroforming process (SHF) was adopted to form a Ti/Al clad metal housing with complex shape. Nowadays, SHF has been widely accepted for the production of components characterized by high surface quality, precise dimensional accuracy together with high drawing ratio. For investigating the formability of the Ti/Al clad metal housing through SHF, the concept of virtual film were developed with explicit finite element method. First, the simulation model was verified by comparing the deformation of the blank obtained from experiments. Through finite element simulations, several significant process parameters such as holding force, tooling geometry, blank dimensions, single-stage (with pre-bulging effect) and multi-stages SHF were analyzed for improving formability of the Ti / Al clad metal housing during SHF.

Study on Thinning of a Boron-Doped Polycrystalline Diamond Wheel-Tool by Micro Rotary W-EDM Approach

2012 ◽  
Vol 217-219 ◽  
pp. 2167-2170 ◽  
Author(s):  
Shun Tong Chen ◽  
Chih Hsien Chang
Keyword(s):  
Electrical Discharge Machining ◽  
High Surface ◽  
Polycrystalline Diamond ◽  
Diamond Wheel ◽  
Power Sources ◽  
High Surface Quality ◽  
Boron Doped ◽  
Novel Approach ◽  
Rc Circuit ◽  
Transistor Circuit

This study presents a novel approach for using a micro rotary wire Electrical Discharge Machining (micro w-EDM) to thin the grinding-edge of a wheel-tool made from boron-doped polycrystalline composite diamond (PCD). For thinning the PCD, two discharge circuits (a Resistance-Capacitance (RC) circuit and a transistor) were used as power sources to obtain a grinding-edge of less than 10 µm in thickness and high surface quality. The wheel-blank is vertically mounted on a spindle and while rotating is thinned by micro w-EDM along a planned computer numerically controlled path. Experimental results verify that boron-doped PCD can be successfully thinned down to 5 µm in edge-thickness. The study shows it is possible to break (cut) diamonds of 10-µm grain size, leaving smooth surface-exposed diamonds at the cutting edge of the wheel tool. The dimensional and geometrical accuracy of the wheel-tool can be exactly controlled. Raman analysis reveals graphitizing of the PCD caused by local high temperature spark erosion at a peak of 1593 cm-1 in RC discharge circuit machining. The peak at 1332 cm-1 for the transistor circuit method indicates diamond sp3 structure. The surface degenerating layer produced by transistor circuit machining gives a suitably thin grinding edge with exposed diamond grains.

Design of Pipeline Composite Repairs: From Lab Scale Tests to FEA and Full Scale Testing

2014 ◽  
Author(s):  
Remy Her ◽  
Jacques Renard ◽  
Vincent Gaffard ◽  
Yves Favry ◽  
Paul Wiet
Keyword(s):  
Finite Element ◽  
Full Scale ◽  
Combined Loading ◽  
Material Strength ◽  
Repair System ◽  
Loading Conditions ◽  
Original Design ◽  
Composite Repair ◽  
Repair Systems ◽  
Composite Properties

Composite repair systems are used for many years to restore locally the pipe strength where it has been affected by damage such as wall thickness reduction due to corrosion, dent, lamination or cracks. Composite repair systems are commonly qualified, designed and installed according to ASME PCC2 code or ISO 24817 standard requirements. In both of these codes, the Maximum Allowable Working Pressure (MAWP) of the damaged section must be determined to design the composite repair. To do so, codes such as ASME B31G for example for corrosion, are used. The composite repair systems is designed to “bridge the gap” between the MAWP of the damaged pipe and the original design pressure. The main weakness of available approaches is their applicability to combined loading conditions and various types of defects. The objective of this work is to set-up a “universal” methodology to design the composite repair by finite element calculations with directly taking into consideration the loading conditions and the influence of the defect on pipe strength (whatever its geometry and type). First a program of mechanical tests is defined to allow determining all the composite properties necessary to run the finite elements calculations. It consists in compression and tensile tests in various directions to account for the composite anisotropy and of Arcan tests to determine steel to composite interface behaviors in tension and shear. In parallel, a full scale burst test is performed on a repaired pipe section where a local wall thinning is previously machined. For this test, the composite repair was designed according to ISO 24817. Then, a finite element model integrating damaged pipe and composite repair system is built. It allowed simulating the test, comparing the results with experiments and validating damage models implemented to capture the various possible types of failures. In addition, sensitivity analysis considering composite properties variations evidenced by experiments are run. The composite behavior considered in this study is not time dependent. No degradation of the composite material strength due to ageing is taking into account. The roadmap for the next steps of this work is to clearly identify the ageing mechanisms, to perform tests in relevant conditions and to introduce ageing effects in the design process (and in particular in the composite constitutive laws).

scholarly journals Predictive Computational Model for Damage Behavior of Metal-Matrix Composites Emphasizing the Effect of Particle Size and Volume Fraction

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2143
Author(s):  
Shaimaa I. Gad ◽  
Mohamed A. Attia ◽  
Mohamed A. Hassan ◽  
Ahmed G. El-Shafei
Keyword(s):  
Finite Element ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Particulate Composites ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Zone Method ◽  
Stress Strain ◽  
The Matrix

In this paper, an integrated numerical model is proposed to investigate the effects of particulate size and volume fraction on the deformation, damage, and failure behaviors of particulate-reinforced metal matrix composites (PRMMCs). In the framework of a random microstructure-based finite element modelling, the plastic deformation and ductile cracking of the matrix are, respectively, modelled using Johnson–Cook constitutive relation and Johnson–Cook ductile fracture model. The matrix-particle interface decohesion is simulated by employing the surface-based-cohesive zone method, while the particulate fracture is manipulated by the elastic–brittle cracking model, in which the damage evolution criterion depends on the fracture energy cracking criterion. A 2D nonlinear finite element model was developed using ABAQUS/Explicit commercial program for modelling and analyzing damage mechanisms of silicon carbide reinforced aluminum matrix composites. The predicted results have shown a good agreement with the experimental data in the forms of true stress–strain curves and failure shape. Unlike the existing models, the influence of the volume fraction and size of SiC particles on the deformation, damage mechanism, failure consequences, and stress–strain curve of A359/SiC particulate composites is investigated accounting for the different possible modes of failure simultaneously.

scholarly journals Experimental investigation of the machining characteristics in diamond wire sawing of unidirectional CFRP

2021 ◽  
Author(s):  
Lukas Seeholzer ◽  
Stefan Süssmaier ◽  
Fabian Kneubühler ◽  
Konrad Wegener
Keyword(s):  
Surface Quality ◽  
Influencing Factors ◽  
Material Properties ◽  
High Surface ◽  
Workpiece Surface ◽  
High Surface Quality ◽  
High Productivity ◽  
Surface Temperatures ◽  
Process Forces ◽  
The Wire

AbstractEspecially for slicing hard and brittle materials, wire sawing with electroplated diamond wires is widely used since it combines a high surface quality with a minimum kerf loss. Furthermore, it allows a high productivity by machining multiple workpieces simultaneously. During the machining operation, the wire/workpiece interaction and thus the material removal conditions with the resulting workpiece quality are determined by the material properties and the process and tool parameters. However, applied to machining of carbon fibre reinforced polymers (CFRP), the process complexity potentially increases due to the anisotropic material properties, the elastic spring back potential of the material, and the distinct mechanical wear due to the highly abrasive carbon fibres. Therefore, this experimental study analyses different combinations of influencing factors with respect to process forces, workpiece surface temperatures at the wire entrance, and the surface quality in wire sawing unidirectional CFRP material. As main influencing factors, the cutting and feed speeds, the density of diamond grains on the wire, the workpiece thickness, and the fibre orientation of the CFRP material are analysed and discussed. For the tested parameter settings, it is found that while the influence of the grain density is negligible, workpiece thickness, cutting and feed speeds affect the process substantially. In addition, higher process forces and workpiece surface temperatures do not necessarily deteriorate the surface quality.

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