Experimentation Investigation of Hard facing Layer by MMAW on Alloy Steel

The wearing of metal parts might be defined as a gradual decay or breakdown of the metal. When a part becomes so deformed that it cannot perform adequately, it must be replaced or rebuilt. While the end results of wear are similar, the causes of wear are different. It is essential to understand the wear factors involved before making a hard surfacing product selection. It would be easy to select a surfacing alloy if all metal components were subjected to only one type of wear. However, a metal part is usually worn by combinations of two or more types of wear. This makes an alloy selection considerably more complicated. A hard surfacing alloy should be chosen as a compromise between each wear factor. The initial focus should centre on the primary wear factor and then the secondary wear factor(s) should be examined. For example: upon examining a worn metal part, it is determined that the primary wear factor is abrasion and the secondary wear factor is light impact. The surfacing alloy chosen should have very good abrasion resistance but also have a fair amount of impact resistance. Keywords: Welding, Hard Facing Electrodes, Alloys, Afrox 300.

CONSTRUCTION OF EMPIRICAL DEPENDENCES OF AXIAL FORCE WHEN DRILLING BILES FROM ALLOY D16 IN ELASTIC DEFORMED STATE

Improving the efficiency of the drilling is an important task in the engineering. Supported by improved board drilling in metal parts, which before drilling elastically deform in the region below the limit of proportionally, which ensures the immutability of other sizes. The experimental way was semi-centered dependence of the axial force when performing blanks from duralumin D16 in elasticly stressful state. These dependences allow you to select the Cor-Rubber cutting modes when drilling parts from duralumin D16.

Experimental and numerical investigation of metal-polymer riveted joints

This paper presents the modeling and analysis of the joints of metal inserts with polyamide 6 using the injection technique. Based on the conducted experiments, modeling and numerical calculations of joints were carried out for various joint configurations. Metal parts, made of steel grade DC 04, are mechanically locked with polyamide 6 (PA6) with rivets. The mechanical connection with rivets of both elements was achieved by filling the holes in the metal parts in the injection process. As part of the work, mechanical-clamp connections made of steel / PA6 were mechanically tested in a single-axis joint tensile test using appropriate tabs. The main goal was to study and numerically analyze the number of rivets and their location on the metal plate for the strength of the connector. An important element of the work was the modeling process of both the PA6 material behavior and the joint itself. As part of the experimental research, the rivet deformation was also observed using computer thermography with the use of an IR camera. The tests and simulation showed that for the sample, the polymer-metal connected with less than three rivets was destroyed by shear. On the other hand, when the polymer-metal junction was made of three rivets, the jamming mechanism was mainly related to damage to the polymer part. For these joints, the maximum values of the breaking force of the joint were obtained in uniaxial tensile and shear tests where three rivets were used. Similar values were obtained during the numerical calculations performed with the use of Abaqus software.

Toward Polymeric and Polymer Composites Impeller Fabrication

Impellers are referred to as a core component of turbomachinery. The use of impellers in various applications is considered an integral part of the industry. So, increased performance and the optimization of impellers have been the center of attention of a lot of studies. In this regard, studies have been focused on the improvement of the efficiency of rotary machines through aerodynamic optimization, using high-performance materials and suitable manufacturing processes. As such, the use of polymers and polymer composites due to their lower weight when compared to metals has been the focus of studies. On the other hand, methods of the manufacturing process for polymer and polymer composite impellers such as conventional impeller manufacturing, injection molding and additive manufacturing can offer higher economic efficiency than similar metal parts. In this study, polymeric and polymer composites impellers are discussed and conclusions are drawn according to the manufacturing methods. Studies have shown promising results for the replacement of polymers and polymer composites instead of metals with respect to a suitable temperature range. In general, polymers showed a good ability to fabricate the impellers, however in more difficult working conditions considering the need for a substance with higher physical and mechanical properties necessitates the use of composite polymers. However, in some applications, the use of these materials needs further research and development.

AUTOMATION OF SHEET METAL COMBINATION DIE DESIGN PROCESS

This paper proposed a novel methodology for designing and manufacturing of sheet metal dies based on features of sheet parts. Also, combination is designed according to die cupping and punching features of sheet metal parts. The proposed approach is an attempt to make seamless integration of computer aided design with computer aided manufacturing. The features used in this study are taken from MusumiTM Catalogue as well as from various small and medium scale sheet metal industries. Work is divided into two phases. In the first phase, the relevant geometrical and topological data is extracted by reading STEP AP 203. In the second phase, a combine adjacency matrix and rule-based system is developed to recognize sheet metal features for die manufacturing. The system showed excellent performance for all types of features contained in the MusumiTM catalog and for different sheet metal industries. The proposed system for automated design of combination dies for sheet metal parts has been tested successfully for various types of industrial deep drawn parts. It reduces the die compoment design time from hours to minutes. selection of die components and drawings generated by the system were found to be reasonable and very similar to those actually used in the sheet metal industries for production of these typical components on combination dies.

Hybrid Manufacturing of Stiffening Grooves in Additive Deposited Thin Parts

This paper is focused on the hybridization of additive manufacturing with single-point incremental forming to produce stiffening grooves in thin metal parts. An analytical model built upon in-plane stretching of a membrane is provided to determine the tool force as a function of the required groove depth and to estimate the maximum allowable groove depth that can be formed without tearing. The results for additively deposited stainless-steel sheets show that the proposed analytical model can replicate incremental plastic deformation of the stiffening grooves in good agreement with experimental observations and measurements. Anisotropy and lower formability caused by the dendritic-based microstructure of the additively deposited stainless-steel sheets justifies the reason why the maximum allowable depth of the stiffening grooves is approximately 27% smaller than that obtained for the wrought commercial sheets of the same material that are used for comparison purposes.

The Role of Stress–Strain State of Gas Turbine Engine Metal Parts in Predicting Their Safe Life

The influence of various factors on the workability of critical metallic parts of a gas turbine engine (GTE) is analysed and systematized. As shown, compressor blades fail as a result of foreign-objects’ damage, gas corrosion, and erosion. Compressor blade roots in most cases fail due to fretting wear caused by vibrations, while the fir-tree rim of turbine discs fails due to low-cycle fatigue (LCF) damage and creep. An increase in the radial gaps between the rotor and stator of the turbine reduces the thrust force and causes changes in the gas-dynamic loading of the engine components. Additional oxidation of metal parts is observed under the action of hot gases from the combustion chamber. The principles of material selection for manufacturing turbine blades and disks, concepts of alloying heat-resistant alloys, and modern methods of surface engineering due to applying protective oxidation-resistant coatings, in particular, chemical vapour deposition (CDV), physical vapour deposition (PVD), air plasma spraying (APS), etc., are also described. To predict the lifetime of turbine disks, it is proposed to use the modified Walker model and Miner’s rule. To specify the time before the failure of the metal blades of the turbine, it is proposed to use the finite element method. To monitor the working-surfaces’ deformations of the gas turbine engine, it is recommended to use optical-digital methods.