| The connecting rod is the important component in the automobile, the ship and so on. In the present market, the cracking technology of the connecting rod is used more and more. The process is short, the grinding and the mechanical cutting of the connecting rod are neglected. Cracking connecting rod is very strict to the material. In the actual production, the cracking is not open and the big hole deformation is bad. In order to break through the limit of the cracking material and solve the cracking problem encountered in the cracking process of connecting rod, this paper proposes the use of investment casting process to produce the double metal cracking connecting rod.In this paper, numerical simulation and practical methods are used to solve the problem of shrinkage porosity, gas and thermal cracking, and to improve the bonding strength of the interface. The main body of the connecting rod is made of low carbon steel, and the cracking material is made of high carbon steel. Through the investment casting process, the two materials are combined to realize metallurgical bonding, and the cracking material is further expanded by the slow cooling of the casting in the mold shell, which is convenient for the cracking of the connecting rod. The main research work and conclusions of this paper are as follows:(1) In this paper, ProCAST is used to simulate the casting process of the double metal connecting rod. The filling solidification process and effective stress distribution were investigated with the casting requirements of Pouring Scheme. Through the orthogonal experiment, the maximum value of shrinkage porosity, effective stress and deformation is judged. The optimum technological parameters of investment casting of double metal rod are obtained.(2) The simulation of the double metal interface is carried out, and the diffusion performance is evaluated. To ambassador to double metal reached diffusion conditions of liquid and solid volume ratio was 12:1 ~ 24:1 and serrated cracking material binding quality is better than the flat, the optimal time intervals between the main casting materials is 0 ~ 20 s.(3) Apply the designed experimental program and obtaining optimum parameters to specific tests to verify the reliability of the design scheme. Change the normal investment casting process. Roast the shell first into the roaster, and then cracking material is inserted after roasting the shell, seal both ends using the refractory clay, at last pour into the body material, such a way that the cracking materials to avoid oxidation questions due to the high temperature roasting. It’s good at the junction of the two metals which have no casting defects.(4) The microstructure and mechanical properties of the bimetallic samples were analyzed. By stretching the samples, it is found that the structure is good and the composition of the elements diffusion, the interface bonding strength is high. After breaking the cracking material, the interface is smooth and brittle, which is in accordance with the requirement of splitting of connecting rod. The above provide a certain basis for the forging of connecting rodIn conclusion, investment casting of double metal connecting rod is reasonable. The experimental and simulation results proved that the double metal samples meet the mechanics performance and cracking of connecting rod. This technology can enlarge the scope of the choice of materials, improving the quality of the cracking. |
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