Reasons for Doping Rare Earth Elements in Molybdenum Alloys

Molybdenum alloy generally refers to a non-ferrous alloy composed of molybdenum as the matrix and other elements added. It has good high temperature strength, low temperature plasticity, thermal conductivity, electrical conductivity and corrosion resistance, as well as low expansion coefficient and other characteristics. It is widely used in heating elements, radiation shielding materials, forging dies and sputtering layer materials, etc. Its added alloying elements include titanium, zirconium, hafnium, tungsten and rare earth elements.

The research shows that the main reasons for the doping of rare earth elements in molybdenum alloys are: 1) it is beneficial to refine the grains, purify the grain boundaries, improve the bending resistance and room temperature toughness of the alloy; 2) compared with pure molybdenum, the rare earth oxides doping The hetero-molybdenum alloy has higher recrystallization temperature and room temperature strength, and has better high temperature sag resistance; 3) Within a certain addition range, with the increase of rare earth oxide content, the prepared molybdenum alloy strength and recrystallization The temperature will be higher; 4) Molybdenum alloys containing rare earth materials have excellent creep resistance and ductility.

However, the current rare earth oxide doped molybdenum alloys have the following problems in the production and use process: 1) the size of the second phase particles is not easy to control; 2) the grain refinement effect of the molybdenum alloy is not obvious; 3) the product The processing quality and service life are low; 4) The high temperature structure stability of the product is poor; 5) It is easy to introduce impurities in the production process, thereby reducing the product quality.

In order to effectively solve the above problems, the researchers proposed a new preparation method of rare earth oxide doped molybdenum alloy. The specific steps are as follows: 1) Reducing rare earth ammonium dimolybdate with hydrogen into nano rare earth oxide doped molybdenum alloy 2) Cold isostatic pressing of alloy powder into molybdenum slab, post sintering, forging and billeting, and then multiple passes of cross rolling; 3) The rolled product is annealed and cold rolled into molybdenum slab. Plate, molybdenum plate after alkaline washing and annealing, you can get the desired product.

The advantages of this production technology are that the process is simple, the size of the rare earth oxide particles in the molybdenum plate can be effectively controlled, and the distribution is uniform, which can effectively avoid crack propagation and damage during processing and application, so as to improve the yield and service life of products.