Effect of Ti content on Magnetic and Electrochemical Corrosion Properties of FeCoCrNi High Entropy Alloys

FeCoCrNiTi _X (X = 0.5,0.75,1) series high entropy alloys with different contents were prepared by vacuum arc melting method. The effects of Ti content on the magnetic properties and electrochemical corrosion properties of FeCoCrNi high entropy alloys were studied by SEM, XRD, VSM, hardness tester and other methods. The experimental results show that the face-centered cubic structure composed of many plate-like structures between dendrites and interdendritic is found in the as-cast alloy of CoCrFeNiTi _x . With the further increase of Ti content, the volume fraction of Laves phase increases, and the morphology of Laves phase changes from granular to reticular structure. The hardness of the alloy increased with Ti content at x = 0.5 to x = 0.75, but decrease when Ti reached x = 1.Compared to FeCoCrNiTi _0.5 and FeCoCrNiTi _0.75 alloys, FeCoCrNiTi ₁ alloys has a wider hysteresis area, while FeCoCrNiTi _0.75 alloys has the smallest hysteresis. When the content of Ti continues to increase to 1 at.%, the paramagnetism of FeCoCrNiTi weakens. The FeCoCrNiTi ₁ alloy presents the largest semicircle radius of the Nyquist curve and the highest diffusion impedance. With the increase of Ti element in the alloy, the diameter of the semicircular arc decreases at first and then increases, and FeCoCrNiTi ₁ has better corrosion resistance.