Installation of Centrifugal Casting of Aluminum Cast Iron in the Process of Self-Spreading High-Temperature Synthesis

Author Name(s): Artur M. Mingaleev, Nikolay N. Safronov, Lenar R. Kharisov
Author Email: ln271@mail.ru

Abstract

The article proposes a technology for producing castings from aluminum cast iron with an aluminum content of 10 … 19% by centrifugal SHS casting, which is an environmentally friendly production and ensures the production of castings with high mechanical properties for structural materials. Due to the structural features of aluminum cast irons, they have high hardness and fragility, which is why they are unsuitable as a structural material. However, in view of the low density, which is 5600 … 6000 kg / m³, its use for cast parts helps to reduce their mass, which has a positive effect on the quality of automotive products. In addition, the discussed aluminum cast iron has heat resistance and wear resistance. It is proposed to use self-propagating high temperature synthesis (SHS) to produce aluminum cast iron. As starting materials, dispersed wastes of the forge and foundry of KamAZ PJSC were used. To clean the blacksmith scale and aluminum shavings and ensure the necessary dispersion, a vibrating screen was designed, as well as a centrifugal casting unit for the SHS process. A centrifugal casting plant with a vertical axis of rotation, in the drum of which six graphite reactors were insulated with asbestos and nichrome thread for further annealing.

Introduction

The object of study is aluminum cast iron containing 10-19% aluminum. A feature of such aluminum cast irons is that they crystallize in a mold using a metastable mechanism, i.e., in its structure, carbon is in a bound state. The structure of these aluminum cast irons consists of two phases, namely: aluminum-doped ferrite and γ ′ phase, which is a carbide-type compound Fe3AlCX. These phases are characterized by high hardness. The microhardness of ferrite is HV 360-400, and the microhardness of the γ ′ phase is even greater than HV 640-850. The amount of γ ′ phase depends on the content of aluminum and carbon [1]. Due to the structural features of aluminum cast irons, they have high hardness and fragility, which is why they are unsuitable as a structural material. However, in view of the low density, which is 5600 … 6000 kg / m³, its use for cast parts helps to reduce their mass, which has a positive effect on the quality of automotive products. In addition, the discussed aluminum cast iron has heat resistance and wear resistance [2]

Conclusion

Thus, technology has been proposed for producing castings from aluminum cast iron with an aluminum content of 10 … 19% by centrifugal SHS casting, they crystallize by a metastable mechanism, that is, in its structure carbon is in a bound state. The structure of these aluminum cast irons consists of two phases, namely: aluminum-doped ferrite and γ ′ phase, which is a carbide-type compound Fe3AlCX. These phases are characterized by high hardness. The microhardness of ferrite is HV 360-400, and the microhardness of the γ ′ phase is even greater than HV 640-850. Due to the structural features of aluminum cast irons, they have high hardness and fragility, which is why they are unsuitable as a structural material. However, in view of the low density, which is 5600 … 6000 kg / m³, its use for cast parts helps to reduce their mass, which has a positive effect on the quality of automotive products. In addition, the discussed aluminum cast iron has heat resistance and wear resistance.

472 total views, no views today

Download PDF File

About the author: admin