Innovative decisions of fastening of all-metal and porous metal bodies with the help of gluing
The goal of the work is to establish the influence of the adhesive composition and the method of surface preparation on the quality of precise one-piece composite compounds based on glue adhesive connections, to ensure reliable fastening in operating conditions in air, water and oil environments; to develop recommendations to increase the effectiveness of the adhesive strength. The scientific novelty of the work consists in the study of conceptual methods of fastening of integral parts in hard-to-fasten connections based on an all-metal base and porous inserts (metal - porous body - metal (MPBM) or metal-porous body (MPB)). The introduction contains brief information about the use of titanium products and methods of connection of their constituent parts by gluing polymer compositions. In the main part, the paper describes the methodology of research to determine the quality of glued compounds of hard-bonded MPB and MPBM based on titanium alloys. The influence of the method of preparation of the glued surface on the tensile strength of the resulting blanks was studied and confirmed by experimental data. It has been experimentally established that the use of additives in the adhesive increases the strength of the MPBM or MPB compound by more than 6.4 MPa (38 %). The paper shows that the application of the method of changing the morphology of the surface layer of a porous titanium tablet in MPBM (smoothing) achieves the best results under normal operating conditions. In the case of artificial aging of samples in water environments, this method of surface improvement exceeds the tensile strength of samples by more than seven times after aging in an oil environment compared to samples undergoing a similar process in water. An alternative method of removal of a number of acrylic adhesives of the DP 8805NS type with the metal surface is developed and proposed. The results of the research will be useful for mechanical engineers for choosing method of fastening of MPBM and MPD, as well as when choosing the appropriate adhesive grades.