Technological quality assurance of the surface layer and operational properties of machine parts by electroerosion treatment

Dependences for determining geometric, physical and mechanical parameters of the surface layer quality, wear resistance, corrosion rate and endurance limit depending on the modes and conditions of electroerosion treatment of machine parts have been given. These dependences allow determining optimal modes and conditions of electroerosion treatment to ensure the required parameters of the quality of the surface layer (with a two–stage approach - design and technological support of operational properties), wear resistance, corrosion rate and endurance limit (with a single-stage approach - direct technological support).

A normalized method for determining the influence on the fixed joints tightness using the technology of the sealing surface job

The existing approaches for determining and evaluating the sealing properties of seals for fixed sealants, as well as methods of leakage monitoring are considered. The description of a normalized method for leak-tightness assessment is given, which allows solving a sufficiently large number of evaluation tasks, for example, technological task: assessment of the influence of the technology sealing surfaced job; design: assessment of the influence of the seals surface layer quality of sealants and geometric parameters of them on sealing capacity (service property).

INVESTIGATIONS OF TECHNOLOGICAL PARAMETERS IMPACT UPON QUALITY FORMATION IN SURFACE LAYER OF PARTS AT CENTRIFUGAL ROTARY PROCESSING

In the paper there are carried out investigations on the definition of the basic technological parameters impact of centrifugal-rotary processing in abrasive environment upon formation of surface layer quality in the parts worked. There is used a finite element method of deformation modeling in granulated massive rotating under the impact of centrifugal forces with the use of the (Comsol Multiphysics) packet. On the basis of computer the high-speed shooting processing and theoretical investigations of the process dynamics there are defined distributions of pressures and granule motion speed in the working chamber. A specified model of abrasive granule encounter with the surface worked at the centrifugal rotary processing on the basis of the modern researches and analysis with the use of the Ansys software. The dependences are obtained for the definition of the maximum penetration depth of environment particles into the surface of the part worked, metal removal, surface roughness which adequacy is confirmed by the results of experimental investigations. There is developed a specified procedure for the computation of roughness height parameters of the surface worked and machining capacity. A specified procedure for the computation of metal removal from the surface worked of parts is offered. An algorithm for the optimization of an engineering process is developed. The investigation results are introduced into production.

THE RATIONALE FOR THE ASSIGNMENT OF CUTTING DATA TO ENSURE THE REQUIRED QUALITY OF THE MATERIAL OF THE SURFACE LAYER DETAILS

The justification of the feasibility of determining the cutting modes when processing with a blade tool with optimization to minimize the wear of the cutting wear is given, i.e. for its maximum resistance and at the same time to ensure the required quality indicators of the material of the surface layer of the part after processing. The initial data for the calculation and examples of calculating the cutting mode and surface layer quality indicators are given. Nomograms for determining the cutting modes, taking into account the quality indicators of the surface layer, are of practical interest for technologists of machine-building enterprises.

SURFACE ROUGHNESS IMPROVEMENT OF PARTS MADE OF POLYMERIC MATERIALS OBTAINED BY MEANS OF ADDITIVE TECHNOLOGIES

In the paper there is under consideration an effort to achieve the roughness index of Ra <0.8 with the aid of soft abrasive tool use. As a result the purpose of this work became development of the technology for surface quality improvement of parts manufactured with the aid of additive technologies. The authors carried out a number of experiments with the samples manufactured with the aid of the method of FDM print. With the aid of 3D Ultra 3 printer of EnvisionTec company. The samples were made of ABS-plastic in the amount of 6 pieces. On each sample there were defects after printing which contributed to the deterioration of surface quality in products. By means of TR220 profilometer there was measured roughness before and after the experiment. There was carried out dry processing and with the use of SCL. As a result, dry processing resulted in worsening surface quality, heavy wear of an abrasive tool and grain contamination. Analyzing the data obtained from the profilometer in the experiment and SCL use a considerable improvement of the surface layer quality at minimum allowance is observed. Investigation methods: in the work basis there are experimental methods of investigation. The investigations are carried out with the use of a microscope and profilometer. Processing investigation results was carried out as a result of the comparison of the measuring data obtained. Work Novelty: there are defined conditions of soft abrasive tool operation and SCL impact upon Ra indices. The results obtained indicate a possibility of Ra improvement on a part surface which is achieved due to a combined shaping with the aid of additive technologies and further machining carried out on a single technological basis. The experience without SCL use has shown the overheating possibility the result of which is a meltback and plastic sticking both on the surface, and on abrasive grains of the cutter which is inadmissible and results in considerable worsening of Ra on the surface machined and cutter wear. In view of this the SCL use in finishing is promising, but to achieve better results SCL chemistry must be improved.

Technology to ensure impermeability in fixed split metal joints according to two-stage circuit of design-technological pre-production

A technology for the solution of the problem in ensuring impermeability of fixed split metal joints at two-stage circuit of the design-technological organization in pre-production is carried out. The technology for impermeability support is based on the defined theoretical and empirical dependences of impermeability upon design factors and quality of sealing surfaces; upon table data obtained on potentialities of the processing methods in quality parameter assurance of the surfaces in sealing joints made of corrosion-resistance 08H18H10T steel, and also obtained empirical dependences of surface layer quality parameters upon processing modes.

Influence of Contact Efforts on the Surface Quality of Difficult Profile under Finishing Hardening Machining

This work presents the research and development data in the field of finishing and hardening processes for parts with complicated shape surface. The comparable effectiveness of different surface finishing and hardening processes were studied, and intensification possibilities of processes of vibration finishing - hardening machining of narrow ducts by means of combined methods with metal anodic dissolution were shown. The results of experimental researches of influence of extrusion conditions of granular media on the surface layer quality are presented.