Impact Of HIP On The Structure And Property Of GH3536 Alloy Formed By SLM

As one kind of new additive manufacturing,Selecting laser melting(SLM)technology occupies very important position in the field of rapid prototyping manufacturing with unique advantages and huge potential.However,the quality of the SLM forming metal parts became very concern of the people especially for the commercial aircraft engine metal parts when this technology is rapid,efficient and simple.For the work environment of this part is very poor,in contrast to those parts formed by traditional process,whether the property of these mental parts formed by SLM is good or not,and whether these parts can meet the requirements of the use or not,all this situation can influence directly the security of plane.SLM technology can rapidly manufacture metal parts which have complex structure based on 3 d data,and the technology could reduce the cost of traditional process,but the major drawback of the technology is porosity and crack when forming metal parts.Hot Isostatic Pressure(HIP)technology is one kind of post-treatment technology which integrate high temperature and high Pressure,and the technology is mainly used to improve the density of powder metallurgy.The process can effectively repair the cracks and pores,and optimize the mechanical properties of metal parts.Studying the combination of SLM technology and HIP technology,it is beneficial to the promotion and application of SLM technology.Around GH3536 high temperature nickel base alloy specimen formed by SLM,this paper systematically study the influence of different HIP parameters on the part's ability of repair defects and improve properties with the help of hot isostatic pressing equipment,which parts is manufactured by SLM,and further analyses the optimized situation that heat treatment improve the properties of materials.The microstructure and properties of samples in different states were analyzed and discussed.This study can provide basic reference for the combination of new and traditional technology.First,this paper study the internal defects and mechanical properties of GH3536 alloy parts manufactured by SLM by a series of test methods,such as XRD diffraction,metallurgical structure observation,tensile properties,lasting performance,SEM fracture analysis and so on.The results showed that the internal defects of samples were mainly micro crack and the mechanical properties of samples is obviously anisotropy which these samples is formed by different direction.Second,we use some equipments to appear the microstructure and property of original,for example metallographic microscope(OM),scanning electron microscope(SEM),transmission electron microscopy(TEM)and tensile testing machine and so on,which these parts was treated by HIP,and we also analysis comprehensively the impaction of HIP process on the microstructure and performance of parts.The results showed that crack was repaired,the morphology of micro structure was also changed,some deposition was produced in the grain,a layer of white layer was occurred on the surface of sample,the property of sample was improved,and the character of anisotropic was disappeared,after HIP process.Last,to eliminate the large net precipitates in the crystal boundary and further improve the material property,the HIP samples was treated by HT.The results showed that the tensile property of HIP parts after HT was improved.Moreover,we contrast the tensile property of hot rolled parts and HIP samples,and assess the advantages and disadvantages of two kinds parts.