Influence of Reheating Temperature in Thixoforging Process on Microstructure and Mechanical Properties of Aluminum A356 gear

Subject Areas : Optimization

Mohammad  Bakhshi ¹ (Islamic Azad University, Khomeinishahr Branch)
Amin  Kolahdooz ² (Young Researchers and Elite Clubs, Islamic Azad University, Khomeinishahr Branch, Isfahan, Iran)

Received: 2017-09-23 Accepted : 2017-12-04 Published : 2017-11-22

Keywords: A356, Thixoforging Process, Cooling Slope Method, Semi-Solid,

Abstract :

A356 aluminum alloy is a hypo eutectic Al–Si alloy. It is identified by good mechanical properties and high ductility, as well as excellent casting characteristics and high corrosion resistance. Thixoforging is a semi solid metal forming process that has the potential to produce parts with superior mechanical properties and fine uniform microstructures. In this research, the Thixoforging process was investigated as a parts shaping method that include aluminum alloy forging in two-phase temperature range (paste mode). For this purpose and in order to achieve favorable conditions in the two-phase zone, the influence of reheating temperature on thixoforging process is investigated. The cooling slope method was used to prepare the initial billet. Semi-solid temperature are considered 575, 585 and 595 °C. Attained results show that the finest microstructure (37 micrometer) is obtained in semi-solid temperature of 575°C and holding time of 20 minutes. Also, the hardness and the compressive test are performed in order to find the best mechanical properties. As it is expected, the best mechanical properties (yield stress of 218 MPa, ultimate compressive stress of 466 MPa and hardness of 89 BHN) are achieved in sample with the finest structure.