Preparation And Properties Of TiN Nano Fiber Reinforced Magnesium Matrix Composites

Magnesium has the advantages of light weight, high specific strength and good specific modulus, superior damping performance, strong anti radiation ability and so on, known as“the most promising green engineering materials in the 21 st Century”. In this work, the dense titanium nitride nanofibers prepared by electrostatic spinning method was the reinforcing phase, titanium nitride nano fiber and magnesium powder were mixed by using ball milling methods, through using spark plasma sintering(SPS) method to prepare close to theoretical density of titanium nitride nano fiber reinforced magnesium matrix composites were successfully prepared by. The powder and sintered composite specimens phase composition, microscopic structure and composition distribution were analysed by using XRD,FSEM and EDS that was together with FSEM. And the strength properties and physical properties of titanium nitride nano fiber reinforced magnesium matrix composites were tested. The effects of ball milling parameters, sintering temperature and different addition amount of titanium nitride fibers were discuss respectively. The main conclusion results were as follows:In ammonia atmosphere, the nano fibers prepared by electrospinning can be calcined at900 ? to obtain uniform and continuous TiN nano fibers which the diameters were about50-300 nm and alength was about 30 ?m.In the process of ball milling, the TiN fiber was easy to aggregate when using stearic acid to be the process control agent; the distribution of TiN nano fiber can be effectively dispersed in Mg matrix by using anhydrous alcohol as the process control agent. The milled powders were respectively sintered at 550 ?and 500 ?. The density of the composites sintered at 550 ? was as high as 98%, the composites sintered at 550 ? had better mechanical properties.The content of TiN nano fibers had obvious influence on the composite organization,physical mechanics performance. With the larger content of TiN nano fibers, the hardness increased from 48.1 to 68.3, the compression strength and tensile strength firstly raised and then droped. When the amount of TiN nano fibers were 0.5wt%, the compressive strength both tensile strength reached the optimal value, up to respectively 282 MPa and 153 MPa.Compared with pure magnesium, the both strength were added by 28% and 78% respectively.The fracture morphology of pure magnesium and TiN nano fibers reinforced magnesium matrix composites were surveyed, as well as the technological discuss, the strengthening mechanism was identified as stress transfer enhancement and fine grain strengthening.