Kazan National Research Technical University named after A. N. Tupolev, Kazan, Russia:

R. V. Gavariev, Associate Professor of the Chair for Design and Technology for Machine-Building Industries, Candidate of Technical Sciences, e-mail: gavarievr@mail.ru
I. A. Savin, Head of the Chair for Design and Technology for Machine-Building Industries, Candidate of Technical Sciences, Associate Professor, e-mail: savin.ia@kaichelny.ru

Nizhny Novgorod State Technical University named after R. E. Alekseev, Nizhny Novgorod, Russia:
I. O. Leushin, Head of the Chair for Metallurgical Technologies and Equipment, Doctor of Technical Sciences, Professor, e-mail: igoleu@yandex.ru

Kazan (Volga Region) Federal University, Kazan, Russia:
K. N. Gavarieva, Teacher, e-mail: gavarievakn@mail.ru

The constantly accelerating pace of life and the rapid growth of industry inevitably lead to an increase and toughening of requirements for manufactured products. Therefore, the scope of application of special methods for obtaining blanks is expanding, among which one of the leading places is occupied by the injection molding method (IMM). The advantages of the IMM include, first of all, high productivity and dimensional accuracy of castings, the minimum need for mechanical processing, the possibility of obtaining castings with a complex external configuration, as well as the automation of the process. The main disadvantages are the high cost of molds, as well as the insufficient quality of the resulting castings, primarily the gas subsurface porosity and gas roughness. In most cases, the IMM is used to obtain castings from zinc, copper and aluminum alloys. The most widespread are aluminum alloys, which make it possible to manufacture castings with different properties depending on the alloy grade. For most grades of aluminum alloys, disadvantages associated with sufficiently high melting temperatures and chemical activity when interacting with the mold are inherent. All these factors make the IMM a complex technological process, for which the challenge of insufficient quality of the resulting castings is urgent. Traditionally, this issue is solved by choosing the technological modes of the casting process. However, in some cases, it is very difficult to achieve high quality castings only by selecting technological modes. The authors have proposed an universal method for improving the quality of castings by applying the developed protective coatings on forming surfaces of molds by cathode-ion bombardment (CIB). The paper presents the results of experimental studies proving the effectiveness of the use of wear-resistant coatings obtained by the CIB method of various compositions in comparison with the traditionally used nitriding in terms of gas and surface porosity, as well as the roughness of castings. The economic substantiation of the efficiency of the use of CIB coatings in comparison with nitriding is presented.

1. Goryunov I. I. Injection molds: reference guide. Leningrad : Mashinostroenie, 1973. 256 p.
2. Belopukhov А. К. Technological modes of injection molding. Moscow : Mashinostroenie, 1985. 272 p.
3. Batyshev К. А., Batyshev А. I. Methods of obtaining castings from aluminum alloys. Liteynoe proizvodstvo. 2020. No. 3. pp. 12–15.
4. Borisov G. P. Scientific basis for development of methods for further improving the properties, technical and economic indicators of production of high-quality castings from aluminum alloys. Liteynoe proizvodstvo. 2008. No. 9. pp. 17–24.
5. Gavariev R. V., Savin I. A. Research of the Mechanism of Destruction of Compression Molds for Casting Under Pressure of Color Alloys. Solid State Phenomena. 2018. Vol. 284. pp. 326–331.
6. Gavariev R. V., Savin I. A., Leushin I. O. To the Question of Casting Alloys of Non-ferrous Metals in the Metal Mold. Materials Science Forum. 2019. Vol. 946. pp. 631–635.
7. Dong X., Zhu X., Ji S. Effect of Super Vacuum Assisted High Pressure Die Casting on the Repeatability of Mechanical Properties of Al – Si – Mg – Mn Die-Cast Alloys. Journal of Materials Processing Technology. 2019. Vol. 266. pp. 105–113.
8. Matsiychuk V. V., Kornyuk А. N. Possibilities to improve the efficiency of injection molding technology. Vestnk Kharkovskogo natsionalnogo avtomobilno-dorozhnogo universiteta. 2006. No. 33. pp. 26–28.
9. Rahmalina D., Sukma H. Effect of the processing parameters on the shrinkage defect using a high-pressure die-casting process. IOP Conference Series: Materials Science and Engineering. 2019. Vol. 553. 012037.
10. Timelli G., De Mori A., Haghayeghi R. Effect of pressure cycles and thermal conditions on the reliability of a high-pressure diecast Al alloy heating radiator. Engineering Failure Analysis. 2019. Vol. 105. pp. 276–288.
11. Kotelnikov D. V., Yakubovich Е. А. Analysis of causes of premature failure of the forming parts of die casting molds of aluminum alloys. Sovremennye materialy, tekhnika i tekhnologii. 2019. No. 5. pp. 68–75.
12. Tabakov V. P., Kokorin V. N., Titov Yu. А., Morozov О. I. Increasing the durability of working surfaces of dies and molds parts made of heat-resistant steels. Izvestiya Tulskogo gosudarstvennogo universiteta. Tekhnicheskie nauki. 2017. No. 11-1. pp. 64–68.
13. Gavariev R. V., Savin I. А., Leushin I. О. Improvement of zinc castings surface quality by laminated protective coating. Tsvetnye Metally. 2017. No. 5. pp. 84–88. DOI: 10.17580/tsm.2017.05.13.
14. GOST 5950–2000. Tool alloy steel bars, strips and coils. General specifications. Introduced: 01.01.2020.
15. GOST 1583–93. Aluminium casting alloys. Specifications. Introduced: 01.01.1997.
16. Shin S.-S., Lim K.-M., Park I.-M. Characteristics and microstructure of newly designed Al – Zn-based alloys for the die-casting process. Journal of Alloys and Compounds. 2016. Vol. 671. pp. 517–526.