| Casting technology is the basic technology of national industry,with the development of technology and social progress,a variety of special casting technology came into being in order to meet the requirements of the new era.The advantages of EPC technology(Lost Foam Casting technology),such as simple and flexible design,high precision control of castings,achieving green production and reducing the cost of mass production,etc.,are unmatched by traditional techniques,so the Lost Foam Casting technology has become a research hotspot.However,it also has certain shortcomings of the current.The dry sand it used,with a relatively slow rate of heat transfer,may lead the speed of casting cooling and radiating to slowing down,and thus may cause the crystal grain of the molten metal to be thicker than that of the sand casting,meanwhile the density of organization is also low,the same material castings is relatively poor in the index of wear resistance and other aspects.These salient problems are a great obstacle to the development of EPC.In view of the above problems,combined with the characteristics of EPC process,this paper chooses to cast high chromium cast iron and high manganese steel under the condition of applying additional mechanical vibration so as to study the influence of mechanical vibration on the microstructure and properties of the two materials,and the influence of the amplitude of the vibration parameters on the microstructure and properties of the castings of Lost Foam Casting under vibration condition,then optimize the set of the vibration parameters in the production,for industrial production to do technical preparations.The results show that:(1)after the vibration field with amplitude of 0.32 mm and frequency of 50 Hz is applied,compared with the unused general lost mold casting,the non-metallic inclusions of casting high chromium cast iron become dispersed in the matrix and the volume fraction is reduced by 12.95%.The microstructure is refined and the impact absorption can increase 19.74%,after the heat treatment(heated to 1050? then air-cooled),the organization of high-chromium cast iron is to be refined,evenly distributed,impact absorption can increase 12.05%,in the load of 3kg and 5kg three-body wear test abrasion resistance can increase 14.65% and 10.80%;The distribution of non-metallic inclusions in casthigh-manganese steel in the matrix presents a tendency to diffuse and refine,and the volume fraction is decreased by 9.4%,the carbides were reduced,the grain refinement,the hardness value increased by 16.3%,and the impact absorption was improved 7.2%;After the heat treatment(heated to 1050? then water toughening),the grain of high manganese steel is more small,the impact absorption can be increased by 10.7%,and wear resistance in the impact abrasive wear test increased by 11.11%.(2)After the application of a fixed frequency of 50 Hz but different amplitude of the vibration field,by comparing the castings with vibrations of 0.32 mm,0.48 mm,0.64 mm,respectively,it is found that with the increase in amplitude,the distribution of non-metallic inclusions in cast high chromium cast iron will be more dispersed and the volume fraction continues to decrease,the organization is further refined,the impact absorption energy also increased but the trend also slows down;after heat treatment(heated to 1050? then air-cooled),the high-chromium cast iron will be more refined,the carbide will be further refined,the impact absorption can be further increased but the increase is reduced;The non-metallic inclusions of cast high-manganese steel will be reduced and the distribution will be more dispersed,the grain will be more refined and impact absorption energy will have a certain increase in the trend;after the heat treatment(heated to1050? then water toughening),the high manganese steel organization continued to refine,the impact absorption energy also showed a continuous increase in the trend,wear resistance will continue to improve. |
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