Development of a Cost Model for Vertical Milling Machines to Assess Impact of Lightweighting

Lightweighting is a design strategy to reduce energy consumption through the reduction of mass of a product. Lightweighting can be applied to machine tools to reduce the amount of energy consumed during the use phase. Thus, the energy cost of machine operation will be reduced. One might also hypothesize that since a lighter-weight machine tool requires less material to build, the cost to produce such a machine will be less. However, it may also be the case that lightweighting a machine tool increases its complexity, which will likely drive up the cost to manufacture the machine. To explore the cost drivers associated with building a machine tool, data on the features associated with a wide variety of vertical milling machine tools are collected. Then, empirical cost models are fit to this data. The results from the cost models show that the machine tool mass is a significant cost driver; other key drivers are the number of axes and spindle power. The models are used to predict the cost benefits of lightweighting in terms of mass, which are compared to potential increased manufacturing costs associated with complexities introduced due to lightweighting.

Multi-Response Optimization of process Parameter in Vertical Milling Machine of EN 31 Using Taguchi Method

The purpose of this experimental research is to compare the effectiveness of using Taguchi approaches for multi-response optimization of process parameters in Vertical Milling Machine of EN 31 Material intending to minimize surface roughness and tool wear rate while maximizing material removal rate to improve the productivity of the process with coated carbide insert. Taguchi L9 and Annova have been applied for experimental design and analysis. This experiment shows that feed and depth of cut are factors that are important for tool wear, Depth of cut is a notable factor for Material Removal Rate and feed is the most notable factor for surface roughness. Spindle speed has little effect on tool wear rate, surface roughness, and material removal rate. Mathematical models for three response parameters i.e. tool wear rate, surface roughness, and material removal rate were obtained by regression analysis

Fabrication of Aluminium Metal Matrix Composite by Friction Stir Processing

Friction Stir Processing (FSP) is a new approach for successful fabrication of Aluminium Metal Matrix Composites (AMCs) with required properties of Nitinol (NiTi) Shape Memory Alloys (SMA). This reinforcement agent is used for heightening the mechanical properties of aluminium alloy with Shape Memory Effect but such fabrication was not possible without defects such as critical intermetallic formation between reinforced particles and matrix. So we present a creative strategy to fabricate Al7075-T6/NiTi composites by FSP. It has been found that the groove filling method results in a more homogenous distribution compared to the multi-holes filling method. In this innovative strategy, we are going to use the groove filling method with a new FSP tool design for the linear distribution of reinforcement particles in grooves. This FSP tool will be used with the help of a Vertical Milling Machine.

Wear Behavior of Ceramic-Metal Composites as Tool Material for FSW of Copper

Friction stir welding (FSW) is employed primarily for metals characterized by poor weldability at fusion welding: aluminium, magnesium, titanium and copper alloys as well as stainless steels. The focus of the study was on the feasibility of application of WC-based hardmetal 85WC-Co and TiC-based cermet 80TiC-NiMo as potential tool materials for FSW of copper. The single-pass welding trials of Cu sheets were performed using a vertical milling machine. For better understanding of interactions between the tool and workpiece at welding temperature EDS line scans across the interfaces tool-workpiece after welding as well as after diffusion tests were performed. It was concluded that both tested ceramic-metal composites did not failure during multiple plunges and during the total transverse welding distance of 10 m. Also, significant tool wear was not observed after such a welding distance. The possibility of producing visually defect-free welds using tools from WC- and TiC- based ceramic-metal composites was proved and also mutual diffusion of elements across the interface tool-workpiece was discussed.

Procedure to find out the optimal ranges of process parameters for friction stir welding

The present study deals with the application of sequential procedure (i.e. steepest ascent) to obtain the optimum values of process parameters for conducting friction stir welding (FSW) experiments. A vertical milling machine is modified by fabricating fixture and tool ( H13 material) for performing FSW operation to join AA7039 plates. The steepest ascent technique is employed to design the experiments at different rotational speed, welding speed, and tilt angle. The ultimate tensile strength is considered as a performance characteristic for deciding the optimal levels. The mechanical and metallurgical characteristics of the joints are studied by executing tensile and microhardness tests. It is concluded from the graphical analysis of the steepest ascent technique that the optimal maximum and minimum values are 1812–1325 r/min for rotational speed, 43–26 mm/min for welding speed, and 2°–1.3° for tilt angle, respectively. Besides, optical microscope and scanning electron microscope are utilized for microstructural and fractographic analyses for a better understanding of the process.

Mapping positional accuracy for milling machine table

The article presents a technique for compiling a map of the positional accuracy of the table of a vertical milling machine when a vibration load of various frequencies is applied. A laboratory setup for creating forced oscillations of a cross table has been developed and manufactured. The reasons for the emergence of the highest deviations in specific areas of the working area of the machine tool are analyzed.

Research and improvement of methods of testing machines for geometric and kinematic accuracy

Purpose. To analyze and check for adequacy the known calculation formulas in determining the geometric and kinematic accuracy, statistical and dynamic rigidity and testing the machine for technological reliability. To carry out comparative calculations to simplify the methodology of complex tests of metal-cutting machines of the universal group. To select and improve the measuring equipment during the complex tests of the milling machine. Methodology. The research is based on the use of analytical methods for calculating the static rigidity coefficient, additional calculation of the measuring instrument design due to the gear ratio, the angle of rotation of the lever and the theoretical error of the displacement mechanism based on the known probability distribution theorem. Findings. The formulas of researches of the coefficient of static rigidity, the mechanism of the measuring device, the angle of rotation of the lever, the theoretical error of the mechanism of movement and the density of probability of distribution of the angle of the lever mechanism of the indicator of tangent type has been obtained. Originality. The research has been carried out and the parametric relationship between the static rigidity coefficient in the design of the spindle assembly of the vertical milling machine with the error of the calculations of the design, the departure of the spindle cone and the location between the supports has been established. The values and functional dependences of the amplitude of oscillations on the maximum allowable spindle speeds and feed rates at which the surface roughness of the workpiece reaches the specified geometric limits has been obtained. It is experimentally confirmed that the parameters of the system of pre-planned repairs are directly related to the reliability of the machine. The resource on the accuracy of the machine determines the need for overhaul, and the repair period depends on the service life of parts and elements of the machine. The actual service life should be a multiple of the repair period, as the restoration of the part is planned during the current repair. Practical value. The practical achievement of the obtained results is to confirm the adequacy of the known calculation formulas in determining the geometric and kinematic accuracy, statistical and dynamic rigidity and testing the machine for technological reliability. On the basis of the received analytical and settlement data was made the simplified complex technique of test of the metal-cutting machine during the: testing the machine at idle; testing of the machine when working under load; testing of the machine for geometric and kinematic accuracy; determination of statistical and dynamic rigidity; research of vibration-resistant vertical milling machine; testing of the machine for technological reliability.

Optimization of Milling Process by Taguchi-PSI Method

060A4 steel (Chinese standard) is a steel with good machinability, which is very popularly used in mechanical engineering. Therefore, the study of solutions for improvement of quality and productivity when machining this steel type has great technical and economic significance. In this study, the multi-objective optimization process has been performed when milling this steel type on a vertical milling machine. The cutting tool is a face milling cutter made of High Speed Steel (HSS) material. The effect of spindle speed, feed rate, and cutting depth on surface roughness has been found. The combination of the Taguchi method and PSI method has been applied to determine the optimal value of three input parameters to simultaneously ensure the two criteria of the minimum surface roughness and the maximum Material Removal Rate (MRR). The works which will be done by the authors of this article in the near future has also been presented in the last part of this study.