scholarly journals Optimization in Milling of Polymer Materials for High Quality Surfaces

2021 ◽  
Vol 15 (4) ◽  
pp. 512-520
Author(s):  
Ryota Uchiyama ◽  
Yuki Inoue ◽  
Fumihiro Uchiyama ◽  
Takashi Matsumura ◽  
◽  
...  
Keyword(s):  
Neural Network ◽  
Surface Quality ◽  
Surface Finish ◽  
Cutting Parameters ◽  
Polymer Materials ◽  
Optimization Approach ◽  
High Quality ◽  
Gradient Information ◽  
Surface Finishes ◽  
The Stability

High quality surfaces with transparency are required for manufacturing of plastic products. In cutting of polymer materials, surface quality is sometimes deteriorated by tarnish and/or unequal spaces of area on a surface. The cutting parameters should be determined through understanding of surface finish characteristics. This paper presents an optimization approach in milling of polycarbonate with polycrystal diamond tools in terms of the surface finish. Surfaces are finished with changing the feed rate and the clearance angle of the tool. The surface finishes, then, were observed to classify the deterioration type into welding, adhesion, and the unequal space of cutter marks with measurement of the surface profiles. The measured surface roughnesses are decomposed into the theoretical/geometrical term and the irregular term induced by the thermal and the dynamic effects. A map is presented to characterize the irregular term for the feed rates and the clearance angles. Because the surface roughnesses are measured at discrete sets of the cutting parameters in the actual cutting tests, the process design cannot be conducted to optimize the operation parameters. Therefore, a neural network is applied to associate the cutting parameters with the irregular term in the map. An approach is presented to determine the number of hidden nodes/units in the design of the neural network. Three prominent areas of welding, adhesion, and unequal spaces of the cutter marks, appear in the map of irregular roughness. The map of the surface roughness is made to optimize the cutting process. The applicable feed rates and clearance angles are determined for the tolerable surface roughnesses. The gradient information in the map is used to evaluate the stability/robustness of the surface quality for changing the parameters. The optimum parameters were determined to minimize the gradient information in the applicable feed rates and clearance angles.

scholarly journals Plasma-Stimulated Super-Hydrophilic Surface Finish of Polymers

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2498 ◽  
Author(s):  
Miran Mozetič
Keyword(s):  
Surface Finish ◽  
Photoelectron Spectroscopy ◽  
Oxygen Plasma ◽  
Polymer Materials ◽  
Oxygen Plasma Treatment ◽  
Hydrophilic Surface ◽  
Capacitively Coupled ◽  
Force Microscopy ◽  
The Stability ◽  
Micrometer Scale

Super-hydrophilicity is a desired but rarely reported surface finish of polymer materials, so the methods for achieving such a property represent a great scientific and technological challenge. The methods reported by various authors are reviewed and discussed in this paper. The super-hydrophilic surface finish has been reported for polymers functionalized with oxygen-rich surface functional groups and of rich morphology on the sub-micrometer scale. The oxygen concentration as probed by X-ray photoelectron spectroscopy should be above 30 atomic % and the roughness as determined by atomic force microscopy over a few nm, although most authors reported the roughness was close to 100 nm. A simple one-step oxygen plasma treatment assures for super-hydrophilicity of few polymers only, but the technology enables such a surface finish of almost any fluorine-free polymer providing a capacitively coupled oxygen plasma that enables deposition of minute quantities of inorganic material is applied. More complex methods include deposition of at least one coating, followed by surface activation with oxygen plasma. Fluorinated polymers require treatment with plasma rich in hydrogen to achieve the super-hydrophilic surface finish. The stability upon aging depends largely on the technique used for super-hydrophilization.

scholarly journals On the Surface Quality of CFRTP/Steel Hybrid Structures Machined by AWJM

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 983
Author(s):  
Fermin Bañon ◽  
Bartolome Simonet ◽  
Alejandro Sambruno ◽  
Moises Batista ◽  
Jorge Salguero
Keyword(s):  
Surface Quality ◽  
Surface Finish ◽  
Functional Performance ◽  
Dissimilar Materials ◽  
Steel Structure ◽  
Cutting Parameters ◽  
Travel Speed ◽  
Hybrid Structure ◽  
Hydraulic Pressure ◽  
Reinforced Thermoplastics

The joining of dissimilar materials in a hybrid structure is a line of research of great interest at present. Nevertheless, the machining of materials with different machinability requires specific processes capable of minimizing defectology in both materials and achieving a correct surface finish in terms of functional performance. In this article, abrasive water jet machining of a hybrid carbon fiber-reinforced thermoplastics (CFRTP)/Steel structure and the generated surface finish are studied. A parametric study in two stacking configurations (CFRTP/Steel and Steel/CFRTP) has been established in order to determine the range of cutting parameters that generates the lowest values in terms of arithmetic mean roughness (Ra) and maximum profile height (Rz). The percentage contribution of each cutting parameter has been identified through an ANOVA analysis for each material and stacking configuration. A combination of 420 MPa hydraulic pressure with an abrasive mass flow of 385 g/min and a travel speed of 50 mm/min offers the lowest Ra and Rz values in the CFRTP/Steel configuration. The stacking order is a determining factor, obtaining a better surface quality in a CFRTP/Steel stack. Finally, a series of contour diagrams relating surface quality to machining conditions have been obtained.

scholarly journals Numerical and experimental modal analysis of machine tool spindles accounting for system decay and its application to chatter avoidance.

2021 ◽  
Author(s):  
Omar Gaber
Keyword(s):  
Natural Frequency ◽  
Surface Finish ◽  
Dynamic Stiffness ◽  
System Change ◽  
Cutting Parameters ◽  
Production Constraints ◽  
Vibrational Characteristics ◽  
The Stability ◽  
Cutting System ◽  
Relevant Boundary Condition

Cycle time, which is the time it takes to machine a certain part, has undergone a great deal of scrutiny as it is directly related to a company's profitability. When trying to machine a part as quickly as possible, selecting the wrong cutting parameters will cause chatter. Tight surface finish and thickness tolerances are usually required by customers. Money lost due to rework and scrap from the destructive nature of chatter has driven a significant number of research studies. It is well established that chatter is directly linked to the natural frequency of the cutting system. As the spindle ages, the vibrational characteristics of the system change. The wear in the spindle bearings causes the system stiffness to decline which results in the changing of natural frequency changing. This change causes the stability lobes to shift. This shift could render a usually stable cut unstable, causing poor surface finish. Excessive chatter can also damage the spindle and shorten its usable life. The objective of this study is to predict the vibrational behaviour of a spindle as it ages. This will be done for spindles utilized under different production constraints. A model of the spindle is also developed by exploiting its Dynamic Stiffness Matrix (DSM) and applying the proper boundary conditions. These results will then be compared to the experimental results obtained from tap testing different spindles to validate and tune the model. Once the static (non-spinning) results are confirmed and the spindle model tuned to represent the real system, the DSM formulation will then be extended to include varying rotational speeds and relevant boundary condition for further modelling purposes. Ultimately, the goal of this research is to develop a procedure to be able to select the correct cutting parameters over the life cycle of the spindle while minimizing the number of tap tests done on the spindle.

scholarly journals Numerical and experimental modal analysis of machine tool spindles accounting for system decay and its application to chatter avoidance.

2021 ◽  
Author(s):  
Omar Gaber
Keyword(s):  
Natural Frequency ◽  
Surface Finish ◽  
Dynamic Stiffness ◽  
System Change ◽  
Cutting Parameters ◽  
Production Constraints ◽  
Vibrational Characteristics ◽  
The Stability ◽  
Cutting System ◽  
Relevant Boundary Condition

Cycle time, which is the time it takes to machine a certain part, has undergone a great deal of scrutiny as it is directly related to a company's profitability. When trying to machine a part as quickly as possible, selecting the wrong cutting parameters will cause chatter. Tight surface finish and thickness tolerances are usually required by customers. Money lost due to rework and scrap from the destructive nature of chatter has driven a significant number of research studies. It is well established that chatter is directly linked to the natural frequency of the cutting system. As the spindle ages, the vibrational characteristics of the system change. The wear in the spindle bearings causes the system stiffness to decline which results in the changing of natural frequency changing. This change causes the stability lobes to shift. This shift could render a usually stable cut unstable, causing poor surface finish. Excessive chatter can also damage the spindle and shorten its usable life. The objective of this study is to predict the vibrational behaviour of a spindle as it ages. This will be done for spindles utilized under different production constraints. A model of the spindle is also developed by exploiting its Dynamic Stiffness Matrix (DSM) and applying the proper boundary conditions. These results will then be compared to the experimental results obtained from tap testing different spindles to validate and tune the model. Once the static (non-spinning) results are confirmed and the spindle model tuned to represent the real system, the DSM formulation will then be extended to include varying rotational speeds and relevant boundary condition for further modelling purposes. Ultimately, the goal of this research is to develop a procedure to be able to select the correct cutting parameters over the life cycle of the spindle while minimizing the number of tap tests done on the spindle.

Research on the Process Parameters for High-Speed Cutting

2012 ◽  
Vol 538-541 ◽  
pp. 1294-1298
Author(s):  
Dong Qiang Gao ◽  
Huan Lin ◽  
Zhong Yan Li ◽  
Jiang Miao Yi
Keyword(s):  
Surface Quality ◽  
Tool Life ◽  
Process Parameters ◽  
High Speed ◽  
Cutting Parameters ◽  
High Speed Machining ◽  
Machined Surface ◽  
High Speed Cutting ◽  
Machined Surface Quality ◽  
The Stability

In this paper, it is analyzes process parameters’ influence on the chip deformation, tool life, machined surface quality and the stability of cutting systems in high speed machining. It provides important reference of the choice of cutting parameters for high-speed machining user.

Stable cutting zone prediction in computer numerical control turning based on empirical mode decomposition and artificial neural network approach

2018 ◽  
Vol 41 (1) ◽  
pp. 193-209 ◽  
Author(s):  
Yogesh Shrivastava ◽  
Bhagat Singh
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Surface Quality ◽  
Empirical Mode Decomposition ◽  
Cutting Parameters ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Mode Decomposition ◽  
Cutting Zone ◽  
Tool Chatter

Stable cutting zone prediction is the key requirement for retaining high-productivity with enhanced surface quality of work-piece. Tool chatter is one of the factors responsible for abrupt change in surface quality and productivity. In this research work, an optimum safe cutting zone has been predicted by analyzing the tool chatter so that higher productivity can be achieved. Initially, chatter signals have been recorded by performing experiments at different combinations of cutting parameters on computer numerical control trainer lathe. Further, these recorded signals have been preprocessed by empirical mode decomposition technique, followed by the selection of dominating intrinsic mode functions using Fourier transform. The preprocessed signals have been used to evaluate a new output parameter, that is, chatter index (CI). Artificial neural network (ANN) based on the feedforward backpropagation network has been proposed for predicting tool chatter in turning process. The input machining parameters considered are depth of cut, feed rate and cutting speed. It has also been deduced that from available different transfer functions, the Hyperbolic Tangent transfer function in ANN is best suitable to predict tool chatter severity in turning operation. Moreover, the safe cutting zone has been assessed by evaluating the dependency of CI on cutting parameters. Finally, more experiments have been conducted to validate the obtained cutting zone.

Research Status of Subsequent Machining of Laser Cladding Layers

2020 ◽  
Vol 15 ◽  
Author(s):  
Lei Li ◽  
Yujun Cai ◽  
Guohe Li ◽  
Meng Liu
Keyword(s):  
Tool Wear ◽  
Surface Quality ◽  
Laser Cladding ◽  
Wear Surface ◽  
Chip Formation ◽  
Cutting Temperature ◽  
Dimensional Accuracy ◽  
Cutting Parameters ◽  
Cladding Layer ◽  
Cladding Layers

Background: As an important method of remanufacturing, laser cladding can be used to obtain the parts with specific shapes by stacking materials layer by layer. The formation mechanism of laser cladding determines the “Staircase effect”, which makes the surface quality can hardly meet the dimensional accuracy of the parts. Therefore, the subsequent machining must be performed to improve the dimensional accuracy and surface quality of cladding parts. Methods: In this paper, chip formation, cutting force, cutting temperature, tool wear, surface quality, and optimization of cutting parameters in the subsequent cutting of laser cladding layer are analyzed. Scholars have expounded and studied these five aspects but the cutting mechanism of laser cladding need further research. Results: The characteristics of cladding layer are similar to that of difficult to machine materials, and the change of parameters has a significant impact on the cutting performance. Conclusion: The research status of subsequent machining of cladding layers is summarized, mainly from the aspects of chip formation, cutting force, cutting temperature, tool wear, surface quality, and cutting parameters optimization. Besides, the existing problems and further developments of subsequent machining of cladding layers are pointed out. The efforts are helpful to promote the development and application of laser cladding remanufacturing technology.

Sign in / Sign up

Export Citation Format

Share Document