Abstract: Additive manufacturing is a layer based manufacturing process aimed at producing parts directly from a 3D model. This paper provides a review of key technologies for metal additive manufacturing. It focuses on the effect of important process parameters on the microstructure and mechanical properties of the resulting part. Several materials are considered including aerospace alloys such as titanium (TiAl6V4 “UNS R56400”), aluminum (AlSi10Mg “UNS A03600”), iron-and nickel-based alloys (stainless steel 316L “UNS S31603”, Inconel 718 “UNS N07718”, and Invar 36 FeNi36 “UNS K93600”).
Abstract: This paper deals with the system of roughness measurement, especially with the problem of data filtering and processing the results. Theoretical part describes shortly terms roughness, waviness and shape as surface integrity parameters. During phase of measuring we obtain all these three constituents in common. The most important task of post processing is separation of them. That is possible due to roughness HW and SW filters. Other parts of this paper contain SW data filtering description and philosophy of HW filtering. Last part of this article describes SW filters with basic mathematical apparatus, areas of usage and limitations.
Abstract: Ultrasonic-assisted drilling (UAD) is a new process used for producing holes in the hard-to-cut and brittle materials at high accuracy and surface quality. In this paper, statistically designed experiments were conducted to study the machinability of soda glass in UAD. The machinability was measured in terms of the cutting power, surface roughness Ra and Rz and the linear tool wear. Machining conditions include UAD and conventional drilling (CD), abrasive tool concentration, feedrate, and spindle speed. Analysis of variance (ANOVA) defined the significant factors and their interactions, while statistical models were used to predict the process responses used for assessment of machinability indices.
Abstract: AISI H11 tool steel is a complex tool steel alloy used to manufacture hot forging dies. These dies however have a limited life, which depends upon the working conditions, the tool design, the heat treatment, and the quality of tool steels. In this paper, a novel wire-and powder-based laser metal deposition (WP-LMD) process was investigated to deposit H11 wire and niobium (Nb) powder simultaneously and develop a coating on existing forging dies for enhancing their life. The main aim was the development of a novel WP-LMD process, and consequently a new H11 tool steel with improved toughness and hardness. The developed WP-LMD process was later implemented to build a multilayer block made of the modified H11 tool steel. The overlap ratio was optimized in both, horizontal and vertical, directions, and were found to be 30% and 20% respectively in order to achieve a fully dense coating and avoid pores and unmelted Nb particles. The potential of the WP-LMD can be used to fabricate an outer layer of the modified H11 tool steel with improved toughness and hardness, which ultimately enhances the life of hot forging.
Abstract: Iron-based amorphous foils and metallic aluminum foils are stacked in alternating layer and welding as laminate composites by ultrasound consolidation process with high-frequency acoustic vibrations. It makes the material to play their own advantages as the new focus. In the consolidation process, the most important standard parameters of the mechanical properties of the material are mainly controlled by the normal force, amplitude of the ultrasonic vibration and the travel speed of the sonotrode imposed by the forming. Ultrasonic vibrations, typically 20 kHz, are applied to the foil laterally (along its width) through a sonotrode (welding tool) .In this paper, the optimum parameters of 25μm amplitude, 2.5kN static force and 20mm / s traveling speed are obtained. It is well-known that the microstructure is the most intuitive way to measure the mechanical properties of materials, including hardness and so on. In addition, in this paper, the forming mechanism of Al 1080/ amorphous (Fe-Si-B) and the connection performance of ultrasonic bonding technology are described in detail. scanning electron microscopy (SEM) found that there is a mechanical interface mechanism and metallurgical bonding mechanism. And the recrystallization temperature of aluminum was calculated. The kinetics of interfacial growth at the grain boundary was analyzed. The composition of interfacial material was analyzed by energy dispersive spectroscopy (EDS) in the metallurgical bonding interface of the recrystallized region. It was preliminarily concluded that the Al-rich FeAl3 phase and the AlB2 phase were inferred. In the exfoliation experiment, it was found by X-ray diffractometry (XRD) that the amorphous did not appear to be crystallized. Finally, the laminated materials were tested for mechanical properties.
Abstract: ZnO thin films have been paid more attention by the scientific community because of their long wavelength and high temperature resistance, and the method of preparing ZnO-TFT by magnetron sputtering is one of the most widely recognized technologies. In this paper, the influence factors, such as sputtering power, sputtering oxygen argon ratio and sputtering temperature, are introduced. In this paper, the ZnO thin film substrate materials are analyzed, and the corresponding conclusions are obtained.
Abstract: Lightweight engineering materials that are strong, durable, wear and corrosion resistant are required nowadays in the field of engineering, especially in the automobile industry. This study was to develop a hybrid composite material of palm kernel shell (PKS) and periwinkle shell (PS) particles as reinforcements in pure aluminium matrix. The central composite design (CCD) of the response surface methodology (RSM) was used to carry out the design of experiment (DoE). Stir casting method was used to fabricate the specimens. The DoE gave 20 runs (experimental samples) which were replicated three times each, bringing the total number of runs to 60 for each of the six responses considered, and 360 specimens were fabricated in all. Three experimental values were obtained for each of the 120 runs for the wear rate, creep rate, density, tensile strength, hardness and melting temperature. The average values were determined and recorded. Control specimens with 100 wt. % pure aluminium matrix, 0 wt. % of PKS and PS reinforcement particles were prepared. The results showed that the reinforcement particles had significant improvement on mechanical properties of the pure aluminium.
Abstract: Compared with the traditional air spraying technique and electroplate method, the coating defects of bonded NdFeB magnet, such as the workpiece hanging point, the pinhole, the bubble, have been solved by using the composite powder electrostatic spraying as surface treatment technology, along with the EE epoxy paint as primer coating and PU polyurethane paint as surface coating. The coating of this composite powder electrostatic spraying is uniform and compact, and the coating has strong adhesion and corrosion resistance. This paper gives a detailed introduction to the composite powder electrostatic spraying, including the choice of some important parameters and the unique hanging tools of composite powder electrostatic spraying.
Abstract: At present time tendencies in the development of engineering and technologies in the manufacturing the metal ware need the effective complex impact on material microstructure by methods of different nature. Special attention should be paid to the combined processes of deformational treatment which are constructed on such basic operations as drawing, rolling, pressing, etc. Despite a plenty of studies and high efficiency of combined methods the problem of understanding the scientific grounds for choice the processing parameters which ensure the guaranteed level and high stability of metals and alloys properties has not been solved jet. Medium carbon steel is used for a wide range of metal ware products. Medium carbon steel wire with 0.5 %C was chosen for the experiments. It was subjected to different kinds of deformational processing such as tensile deformation, alternating bending, twisting and their combination. Complex of experimental research was carried out in order to study the influence of different kinds of plastic deformation on the medium carbon steel wire microstructure. By scanning electron-microscope analysis the peculiarities of pearlite behavior after deformational processing with different total deformation degree were studied. The comparative analysis of cementite changing after different kinds of deformation was conducted.