Verification of Monolithic Rotary Cutting Tool For Active Driven Rotation Machining

Forced rotation turning appears to be an effective machining method due to higher tool life, time efficiency and acceptable quality. Several studies have been carried out to investigate the basic characteristics of forced rotation machining. So far, tools are used whose design included several components. However, such tools may generate vibrations, which are undesirable in the process. In engineering practice, most vibration problems are solved by reducing the cutting parameters (cutting speed and feed rate), which reduces machining productivity. For this reason, a new type of monolithic rotary tool has been designed that eliminates the design complexity and high assembly accuracy requirements of current rotary tools. The presented solution fundamentally validates the new monolithic tool for forced rotation technology and defines its application for different machining materials.

The Combination of Taguchi and Proximity Indexed Value Methods for Multi-criteria Decision Making When Milling

Milling is a commonly used method in mechanical machining. This is considered to be the method for the highest productivity among cutting methods. Moreover, the quality of the machined surface is increasingly improved as well as the machining productivity is increasingly enhanced thanks to the development of machine tool and cutting tool manufacturing technology. Therefore, in each specific processing condition (about machine, tool and part material, and other conditions), specific studies are required to determine the value of technological parameters in order to improve productivity and machining accuracy. Only in this way can we take full advantage of the capabilities of modern equipment. The process parameters in the milling method in particular and in the machining and cutting methods in general can be easily adjusted by the machine operator as the parameters of the cutting parameters or the change of tool types. In this article, the combination of Taguchi and Proximity Indexed Value (PIV) methods is presented for multi-criteria decision making in milling. An experimental matrix was designed according to Taguchi method with five input parameters, including the insert materials (TiN, TiCN, and TiAlN), nose radius, cutting velocity, feed rate and depth of cut. The total number of experiments that were performed was twenty-seven. The workpiece used during the experiment was SCM440 steel. At each experiment, the surface roughness was measured and the Material Removal Rate (MRR) was calculated. The weights of these two parameters have been chosen by the decision maker on the basis of consultation with experts. The PIV method was applied to determine the experiment at which the minimum surface roughness and the maximum MRR were simultaneously guaranteed. In addition, the influence of input parameters on surface roughness was also found in this study.

Study on multi-objective optimization of X12M steel milling process by reference ideal method

For all machining cutting methods, surface roughness is a parameter that greatly affects the working ability and life of machine elements. Cutting force is a parameter that not only affects the quality of the machining surface but also affects the durability of cutter and the level of energy consumed during machining. Besides, material removal rate (MRR) is a parameter that reflects machining productivity. Workpiece surface machining with small surface roughness, small cutting force and large MRR is desirable of most machining methods. Milling is a popular machining method in the machine building industry. This is considered to be one of the most productive machining methods, capable of machining many different types of surfaces. With the development of the cutting tool and machine tool manufacturing industries, this method is increasingly guaranteed with high precision, sometimes used as the final finishing method. Milling using a face milling cutter is more productive than using a cylindrical cutter because there are multiple cutter s involved at the same time. This article presents a study of multi-objective optimization of milling process using a face milling cutter. The experimental material used in this study is X12M steel. Taguchi method has been applied to design an orthogonal experimental matrix with 27 experiments (L27). In which, five parameters have been selected as the input parameters of the experimental process including insert material, tool nose radius, cutting speed, feed rate and cutting depth. The Reference Ideal Method (RIM) is applied to determine the value of input parameters to ensure minimum surface roughness, minimum cutting force and maximum MRR. Influence of the input parameters on output parameters is also discussed in this study

Multi-objective optimization of SKD11 Steel Milling Process by Reference Ideal Method

For all machining cutting methods, surface roughness is a parameter that greatly affects the working ability and life of machine elements. Cutting force is a parameter that not only affects the quality of the machining surface but also affects the durability of cutter and the level of energy consumed during machining. Besides, material removal rate (MRR) is a parameter that reflects machining productivity. Workpiece surface machining with small surface roughness, small cutting force and large MRR is desirable of most machining methods. This article presents a study of multi-objective optimization of milling process using a face milling cutter. The experimental material used in this study is SKD11 steel. Taguchi method has been applied to design an orthogonal experimental matrix with 27 experiments (L27). In which, five parameters have been selected as the input parameters of the experimental process including insert material, tool nose radius, cutting speed, feed rate and cutting depth. Reference Ideal Method (RIM) is applied to determine the value of input parameters to ensure minimum surface roughness, minimum cutting force and maximum MRR. Influence of the input parameters on output parameters is also discussed in this study.

Analysis of the compromise between cutting tool life, productivity and roughness during turning of C45 hardened steel

Tool wear and surface roughness as performance indexes are considered to be the most important in terms of hardened materials’ machinability. The best combination of cutting parameters which enhances the compromise between tool life, productivity and machined surface quality contribute to benefice on production cost, which makes manufacturing industry interested in it. The aim of this research is to investigate the life of ceramic cutting tool and machining productivity together with surface roughness during turning of hardened steel C45, with focus on the selection of the optimal cutting parameter combination. The experiments are carried out based on uni-factorial planning methodology of cutting speeds and feed rates. The results show that the mixed ceramic tool is suitable for turning hardened steel C45 (40 HRC) and the conclusion is that it performed well in terms of tool life, productivity and surface quality at a combination of cutting speed (200 m/min), feed (0.08 mm/rev) and depth of cut (0.3 mm). Additionally, a tool life model has been proposed which is presented very high coefficient of determination.

Identification of Analytical Dependencies of the Operational Characteristics of the Workpiece Clamping Mechanisms with the Rotary Movement of the Input Link

The research is devoted to the problem of determining the efficiency of the workpiece fixing mechanism operation. Improving characteristics of workpiece fixing is one of the required conditions to increase the cutting modes, which may help to enhance the machining productivity. The study investigates the main characteristics and general features of a new structure of clamping mechanisms with electromechanical actuators for fixation of rotation bodies. The main advantages of using electromechanical clamping actuators with self-braking gear are presented. Two simplified dynamical models for the description of different stages of the clamping process are developed. The calculation scheme was formulated to find out how the mass-geometric parameters of mechanism elements should influence the main characteristics of the clamping mechanisms of this type.

Effect of Temperature on Tool Wear During Milling of Ti64

In recent years, the development of new, increasingly resistant materials limit machining productivity. This observation is especially true for titanium alloys. The state-of-the-art shows that one of the phenomena responsible for tool wear is temperature. The high temperature is explained by the low thermal conductivity of the alloy and its high mechanical properties. Consequently, high temperatures generated when cutting speeds are increasing lead to very rapid wear phenomena. However in milling, the period during which the insert is not in contact with the material may allow it to cool but its effect is not clearly established. In order to correlate tool wear and cutting temperatures in milling, an experimental bench has been developed. In turning and therefore with a fixed tool, the milling conditions are recreated and allow to measure the temperatures on the cutting face. Two parameters were tested: (i) radial depth, which influences the tooth stress time, and (ii) the cutting speed, which is the fundamental parameter of the cutting temperature. Experimentally, it appears that increasing radial engagement and cutting speed reduces tool life and increases temperatures. However, the phenomenological analysis is not immediate. The relationship between these phenomena is based on a heat balance of the cutting process. The use of an infrared (IR) camera in this problem and a specific analysis method allow observing the temperature gradients on the cutting face making the analysis more robust compared to the thermocouple technic. It thus appears that the increase in radial engagement leads to a higher tool temperature, but the analyses show above all a higher temperature within the insert and therefore more difficult to evacuate.

Influence of processing Parameters on Rust Removal Performance when Cleaning Steel with Ultrasonic Assistance

Ultrasonic steel surface cleaning technology is increasingly playing an important role in many different fields. The determination of the influence of the machining parameters on the amount of removed rust on the steel surface is important in the selection of these parameters to increase the machining productivity. In this study, we conducted tests to determine the influence of machining parameters on the amount of removed rust on the steel surface. Tests were performed according to Box-Behnken matrix in two cases: Acids are used or not used in cleaning solutions. In the absence of the use of acids, the selected parameters were the input parameters of the test including machine power, cleaning time and the distance from the steel surface to the ultrasonic head (referred to as the machining distance). Four parameters have been selected as the input parameters when using acids in the detergent solution, including machine power, machining distance, solution concentration and machining time. Finally, orientation for the next research has also been proposed in this paper.

Mathematical Model of the Tensioning in the Collet Clamping Mechanism with the Rotary Movable Input Link on Spindle Units

Increasing machining productivity causes the cutting forces acting on tools or workpieces to grow and requires extra clamping forces for their fixation reliably. In the research, a mathematical model of the operation of the clamping mechanism for fixating cylindrical objects on the spindle of machine tools at the stage of tension is presented. The presented design of the mechanism contains screw gear and provides self-braking. Based on the calculation model, mathematical dependencies are developed to describe the relationship among the movements of the parts of the mechanism when clamping forces are growing. The presented analytical dependencies allow considering the stage of growing clamping forces separately when the conservative type of forces are prevailing in the mechanism’s operation. That stage of work when both types of forces of dissipative and potential characters exist is considered. The developed dependencies describe the position of parts of the clamping mechanism depending on the generalized coordinate. The angle of rotation of the input rotating link is used as the generalized coordinate. This fact allows calculating the position of the elements of the clamping mechanism of this type depending on time. Results of the research enhance understanding the pattern of the change in the interaction of the elements and forces that act in the mechanism during the final stage of clamping. The obtained mathematical dependencies are a precondition for the development of design methodology for mechanisms of this type.

Remaining useful tool life predictions in turning using Bayesian inference

Tool wear is an important factor in determining machining productivity. In this paper, tool wear is characterized by remaining useful tool life in a turning operation and is predicted using spindle power and a random sample path method of Bayesian inference. Turning tests are performed at different speeds and feed rates using a carbide tool and MS309 steel work material. The spindle power and the tool flank wear are monitored during cutting; the root mean square of the time domain power is found to be sensitive to tool wear. Sample root mean square power growth curves are generated and the probability of each curve being the true growth curve is updated using Bayes’ rule. The updated probabilities are used to determine the remaining useful tool life. Results show good agreement between the predicted tool life and the empirically-determined true remaining life. The proposed method takes into account the uncertainty in tool life and the growth of the root mean square power at the end of tool life and is, therefore, robust and reliable.