Study On Forging Process Of Aluminium Alloy For Automobile Aontrol Arm

Nowadays, the automotive industry are developing toward to the direction of lightweight、 high-speed、saf、comfortable、energy saving and low pollution. Increasing usage rates of aluminum alloys in the automobile is the inevitable trend of the development of automotive industry. The Suspension control arm in the automobile is the important part of the chassis system, which is designed to possess high strength and good reliability, because its properties are related to the safety of the automobile and passengers. In order to achieve the goal of automobile lightweight, aluminum alloys are used to produce the control arm parts in place of steel.In this paper, a new type of6000aluminum alloy is developed to product control arms. The flow stress equations and deformed micro-structure at the various processes for this aluminum alloys are obtained by the thermal simulation experiment in Gleeble3500and EBSD micro-structure observation. Moreover, it is found that the subgrain or recrystal grain decreases with Z value increasing; The relationship between grain size and Z value is:; The grain grows in various degrees after the solution treatment of this alloy, and the degree of grain growth is directly proportional to Z value.The structure of aluminum control arms is optimized and its final structure is determined by analyzing the stress in the aluminum control arms at seven kind of working conditions. Compared with steel control arms, aluminum control arms decrease20%in weight.The complicated forge processes for producing the aluminum control arms is abandoned and a near-net-shape forge process, forge combined with billets with abnormal shape, is used to produce the aluminum control arms. The shapes of abnormal shape billets are designed and forge processes are studied by numerical simulation. It is found that the strain in forge pieces increases firstly, and then decrease with increment of the forge temperature and velocity. By contrasting with the experimental results of the thermal simulation experiment, the shape of the abnormal shape billets is determined and the forge process is obtained, this is, forge temperature is400℃and forge velocity is10mm/s. the control arm produced by this process possesses good properties, that is, The yield strength of the parts is about381.5MPa, the tensile strength of the parts is about401MPa,and the elongation is in the range of12%-15.6%, which can satisfied with the safe usage of the control arms.The study of this paper shows that using the high strength of the new type of6000aluminum alloy combined with the forge process of abnormal shape billets to produce aluminum control arms in the automobile, is a efficient and energy conservation approach.