Mold shell of investment casting cobalt chromium molybdenum artificial joint implant and manufacturing method of mold shell

Abstract

The invention discloses a mold shell of an investment casting cobalt chromium molybdenum artificial joint implant and a manufacturing method of the mold shell and relates to the technical field of metal processing. A mold shell main body is provided with two layers of cobalt chromium molybdenum surface layers; each cobalt chromium molybdenum surface layer is prepared from silica sol, aluminum oxide powder, cobalt aluminate powder, a de-foaming agent, a wetting agent and latex, wherein the mass ratio of the aluminum oxide powder to the silica sol is 4.35 to 4.45 and the mass ratio of cobalt aluminate to the silica sol is 0.22 to 0.35; the mass ratio of the de-foaming agent to the silica sol is 6 to 8ml / Kg; the mass ratio of the wetting agent to the silica sol is 2 to 3ml / Kg and the mass ratio of the latex to the silica sol is 0.03 to 0.05; aluminum oxide slurry containing the cobalt aluminate and the aluminum oxide powder have very high heat conduction performance, a double-surface-layer manner ensures the thickness of a high-heat-conduction layer, the super-cooling degree of metal liquid is increased and the nucleation rate is improved, so that the aim of thinning crystal grains isfinally realized; a certain amount of the latex is added into surface-layer slurry and back-layer slurry and the latex is burnt after being baked, so that a lot of pores are formed in the mold shell,the air permeability of the mold shell is increased and the air pore rejection rate of castings is reduced.

Description

technical field [0001] The invention relates to the technical field of metal processing, in particular to a mold shell of an investment casting cobalt-chromium-molybdenum artificial joint implant and a manufacturing method thereof. Background technique [0002] With the development of society and economy, people's awareness of medical health is getting stronger and stronger, and the demand for cobalt-chromium-molybdenum alloy artificial joint implants is also increasing. If artificial joints want to replace the function of joints, they have very high requirements on material performance. , requires higher strength and toughness. From a metallographic point of view, in order to achieve high strength and high toughness, parts need to have uniform and fine grains. But for cobalt-chromium-molybdenum alloy, the alloy does not have a phase transition point, and fine grains cannot be obtained through post-heat treatment; in addition, the cobalt aluminate grain refiner currently us...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is that the method of obtaining fine grains by lowering the shell temperature and pouring temperature has the risk of insufficient pouring for thin-walled parts, and the fine grains obtained in this way are often uneven, and parts with thick parts are still Possibly coarse grains; pouring in an atmospheric environment or a vacuum environment with a protective atmosphere will result in a large number of pores on the casting

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