Research On High Temperature Performance Of TZM Alloy Plate Of Produceed With Doping La

TZM alloy(0.4%~0.55%Ti,0.06%~0.12%Zr,0.01%~0.04%C,all for Mo) is one of the most widely applied molybdenum alloy because it has high melting point, high strength, high elastic modulus, good corrosion resistance and good mechanics performance. The TZM alloy and La-TZM alloy was prepared by powder metallurgy method, La was joined in the form with lanthanum nitrate or La2O3 powder, joining C elements in the form of stearic acid. The article mainly observated the organization of alloy sintered billet and sheet through metallographic. Thermal simulation experiment of the sintered alloy billet was carried out with Gleeble-3800 hot simulation experiment machine, and the strain rate was respectively 0.1 s-1 and 0.01s-1. Plate detection has high temperature tensile experiments, vickers hardness test and SEM fracture scanning. The main results are as follows:Doped with rare earth element La could refine the organization structure of TZM alloy, had the effect of second phase fine-grain strengthening; The solid grain size of TZM alloy doping alcohol solution of nitric acid lanthanum was more small.. In 0.1 s-1 and 0.01 s-1 strain rate, and deformation of 50%, as the temperature rised, the compressive strength of La-TZM alloy was reduced, and the stress-strain curve were single peak rheological curve, fibrous tissue, and did not appear recrystallization, so softening sample had not happened, the recrystallization temperature was higher than 1200 ℃. Because of heat conduction and uneven deformation degree, the vickers hardness had the obvious difference, the regional central Ⅲ of deformation supreme, area Ⅱ of no deformation zones second, deformation areaⅠlowest. The high temperature tensile strength, yield strength and vickers hardness of La2O3-TZM and La(NO3)3-TZM alloy plate decreased with the increase of temperature, and the high temperature tensile strength decline rate of La(NO3)3-TZM alloy was faster, so the La(NO3)3-TZM alloy high temperature sensitivity was higher. Internal strength and grain or grain boundary strength of the alloy rolling plate were equa l,and the critical temperature was 1200 ℃. As the temperature less than 1400 ℃, the high temperature fracture mode of La2O3-TZM and La(NO3)3-TZM alloy plate were transgranular fracture; When temperature higher than 1400 ℃, the fracture mode of La2O3-TZM and La(NO3)3-TZM alloy plate were based on the intergranular fracture. Therefore, two kinds fracture mode of La-TZM alloy plate turned the transgranular fracture into the intergranular fracture at 1400 ℃, namely the temperature of the same strength with gra in and grain boundary was 1400 ℃.