The Study On Fatifue Of The Dental Co-Cr Alloy By Heat Treatmeat

Clinically people often repair the defect of dentition by cast removable partial denture. There are many merits such as good retention and support , contrivance actively beauty, nimble, good chemistry performance, little foreign body sensation. It is good stability because of good retention sufficiently by oral part. The patients like it because it`s good reparation. cast clasp is the main retainer, so it ensure the artifical teeth enough retention. but with the artifical teeth using, It is very complicated that stuff fatigued, every mechanism mechanical is difficult to avoid fatigue, It is important that study the fatigue broken of the dental material. Dental co-cr alloy is a dicho alloy.The main composition is co and cr. The metal turns from liquid state to solid state when it is casted. Solid metal is crystal after clotting.It effect the disposition of metal that the grain's shape, size, distribution and etc. The grain is more little, the strength and hardness is more higher and the plasticity is more higher. At the same ecto-wear;the shape of the grain is more bigger, the fissuaring is more lower.the hindrance of grain boundary is more lower.This product containing the elements of cobalt,chromium,nickel,molybdenum,etc,The experiment is made up of two parts: to detect the metal phase of co-cr alloy cast, integrate its metal phase and then choose correlation heat treatment craft; to take heat treatment,then take fatigue tests,at last, integrate its metal phase, analysis its mechanismPurpose:Study the influence of CO-Cr alloy by heat treatment,and look for an artwork to elevate it'sfatigueMethod Analysis the metal phase of co-cr alloy cast, integrate its metal phase and then choose correlation heat treatment craft; to take heat treatment,then take fatigue tests,at last, integrate its metal phase, analysis the fatigue mechanismResults The results of metal phase test :Basal body is made of austenite,αphase, co-cr solid melt,and littleεphase and littleσphase ,when it is zoomed in 200 times,the alloy may be saw that basal body phase and crystal phase is well-distributed. When zoomed in1000 times,the basal body phase that be made of co element.It is saw clearly that the shape of grain and carbide,and may be saw some foreign matter ,stoma and crazing.The grain is enlargement,After casted, the dimension of co-cr alloy grain had changed, 51μm to 28um. Fatigue life: A group : 36458 times,heat: 41256times;C 37823timesConclusion1 Heat treatment can enhance the fatigue life of co-cr alloy utility. 2 The better heat treatment is: heat to 1000℃, stubbornαCo, incubate 10 minuets,cooling by warter .and aging for 2 hours at 700℃,then cooling by air and get it out...