Solid liquid segregation is one of the main defects in thick wall products. Under the condition of good feeding condition and complete disappearance of shrinkage cavity and porosity, the performance of a single thick wall product at different positions is quite different. The most intuitive performance is that the...
The influence of process parameters on the shrinkage cavity and porosity in the semi-solid die casting process was studied by using the control variable method, and the causes were analyzed on the basis of empirical theory. (1) The shrinkage cavity and porosity defects in the experiment all appear in...
In the process of analyzing the solid-liquid segregation, in order to identify the bright white cxal grains and the dark liquid phases in the gold phase, Keller reagent was used to corrode the samples for 15 seconds. The treated samples were observed under the metallographic microscope. The solid phase...
Semi solid die casting is different from the traditional liquid die casting, which is mainly reflected in the different slurry characteristics used in the process of die casting. Due to the viscosity characteristics of slurry, it is not easy to produce flow defects such as flying material and air...
In this experiment, the method of controlling variables is adopted. The mold temperature is set as 230 ° C, 140 ° C and 50 ° C respectively under the condition of other parameters unchanged. Through the measurement of actual mold temperature, the temperature at the bottom of the moving...
Shrinkage porosity defect is the key research object of this project. The observation method for this defect is fluorescence penetration method. Its principle is to irradiate the sample surface treated by fluorescent agent, and the penetrant entering into the hole area of the sample surface through penetration will show...
In this test, the control variable method is adopted, and the material handle thickness is set as 16mm, 31mm, 42mm and 68mm respectively under the condition that other parameters remain unchanged. According to the sample preparation and detection method mentioned above, the semi-solid die-casting samples were sawed, polished, fluorescence...
Vickers hardness measurement The unit of hardness measured is micro Vickers hardness. When hv-30 Vickers hardness tester is used, the diamond indenter will slowly drop to the surface to be measured, and the set force will be applied. The holding time of the force is 10s. After the force...
During the preparation of metallographic samples, sawing, cutting, grinding, polishing and other processes are required. After the blank samples to be observed are cut out from the castings, the observation surfaces of the samples are first polished with abrasive paper with particle sizes of 100, 200, 800, 1000 and...
In this test, the method of variable control was adopted. Under the condition of other parameters unchanged, the boosting pressure was set to 200bar, 500bar, 800bar and loobar respectively for die casting. According to the sample preparation and detection methods, the semi-solid die casting samples were analyzed by sawing,...