In practical production, the shape of castings is usually irregular, and the wall thickness varies greatly. These factors have an important impact on the solidification structure and properties of castings. In order to explore the influence of the casting wall thickness on the structure of the castings made by vibration lost foam casting, according to the previous experimental results, the vibration process parameters with the vibration frequency of 35Hz and the amplitude of 3mm were selected, and the double step sample was used. Its structure is shown in the figure.
The wall thicknesses of the samples were 10, 20, 30, 40, 50 and 60mm respectively. During the test, fesimg8re3 alloy was used as spheroidizing agent and 75fesi was used as inoculant. The addition amounts were 1.4% and 0.4% of the burden weight respectively. The treatment temperature was 1510 ° C. After pouring, take samples at the center of the step for metallographic observation, and the sampling position is shown in the figure. The effect of sample wall thickness on the microstructure of nodular cast iron in vibration lost foam casting was studied.