Experiments Study On Liquid Sintering Preparation Of Tungsten-based Alloy Shielding Material

At present, the common used shielding material is lead alloy. However, lead alloyhas many shortcomings including lead to secondary bremsstrahlung, poor hardness,poor structural performance in manufacture of large size component, and lowmechanical strength, besides lead itself is a kind of heavy metal pollution source,which is likely to cause heavy metal poisoning in the course of applications，so it isgradually restricted. Tungsten has a strong anti-γ-ray capacity due to its high atomicnumber, so it is used as a new type of shielding material because it has manyadvantages like high density, strong anti-γ-ray capacity, high strength, non-toxicenvironmentally friendly and so on. This topic using a tungsten-nickel alloy to replacelead alloy as a nontoxic and environmental protection shielding materials. Traditionaltungsten-nickel alloy is common used the technology of powder metallurgy tomanufacture. This project that utilized laser rapid prototyping based on liquid-phasesintering method to prepare tungsten-nickel alloy is significant.The main research contents of this paper are:1. Preparation of tungsten copper alloy. Adopting the modification of hydrogenfurnace sintering contain copper quantity were5%,10%,15%,20%of tungstencopper alloy, through the drainage method test the density of tungsten copper alloy,and the different components of tungsten copper alloy shielding property andmechanical performance testing, and using optical microscope of tungsten copperalloy microstructure, The studies show that the existing equipment rated temperatureis lower, so make tungsten copper alloy liquid sintering temperature lower, heatpreservation time is short, the preparation of the tungsten copper alloy in the densityis about8.3g/cm~3, shielding of half the thickness of the absorption is about11mm,tensile strength is between20and30MPa. 2.By liquid phase sintering of hydrogen furnace and laser sintering preparatedcontent of10%tungsten nickel alloy, using a homemade shear device testing sampleshear strength, testing the hardness of sample by Rockwell hardness. the resultsshow that the laser power of1000W,W90Ni10of tungsten-nickel alloy shearstrength is112MPa, Rockwell hardness, shear to brittle fracture, by scanning electronmicroscopy analysis that we find the fracture of large shear slip bands.3.Tungsten-nickel alloy was prepared by laser rapid prototyping. Theexperimental results show that: the preparation of laser rapid prototyping of tungstennickel alloy W94Ni6shielding performance, can find that the preparation of laserrapid prototyping tungsten nickel alloy has the very good shielding characteristics,for γ photon energy of0.551Mev gamma source, absorb the same amount of gammarays of the need W94Ni6tungsten nickel alloy for63.4%of the thickness of the lead,and the preparation of laser rapid prototyping tungsten nickel alloy of hardness is54.2HRC, equivalent to574HBS,64%higher than the pure tungsten, observationof tungsten nickel alloy microstructure found, tungsten nickel alloy for themicrostructure of interstitial, it contains holes less, in addition to certain tungsten ornickel was formed after high temperature oxidation metal oxide inclusions.In this paper, experimental results show that the laser as the energy of theliquid-phase sintering method have good effect and feasibility.