Chemical Processes And Technology Research, Cast Nickel-phosphorous Alloy

At present, the miniature bellows spring used in infrared self-adjusting throttle cooler and torpedoes fusing, mainly made through pure nickel electroforming or relying on imports. Due to the distribution of power lines, electroformed miniature bellows spring is troubled by the problem of thickness difference between bellow's peak and valley, meanwhile the spring rigidity also could not meet the requirements; In electroforming, the sulfur in pure nickel can also cause welding brittleness. Electroless deposition can solve issues such as welding brittle and thickness difference, but the texture of Ni-P alloy could also cause more brittleness. The purpose of this paper is to develop a Ni-P alloy miniature bellows spring with good ductility, low stress, nice surface glossiness, Good thickness uniformity and also has a good rigidity, to meet domestic need in infrared self-adjusting throttle cooler and torpedoes fusing.Electroless casting and electroless plating are according to the principle of electroless deposition process, The aim of electroless plating is make a protective coating with a piece of work which needed to form a protective layer of protection, And electroless casting the purpose of forming a certain independent entity parts with the mechanical properties.Through a large number of parallel and orthogonal experiments, eventually, the electroless forming miniature bellows spring fully meet the designed requirements: phosphorus content3-8%; rigidity>1700g/cm2; part's uniformity reached 90%, sickness 50+5μm; also with good weld ability and suitability for subsequent machining process, and the surface was semi-bright.The experiment shown out that complexant, main salt and reducing agent can cause changes in phosphorus content of the casting layer, stirring, adjusting pH value and temperature of the casting solution will also affect cast layer's phosphorus content, lactic acid+sodium succinate complexant could obtain a low phosphorus layer, and also could improve the solution's stability; Additive TN1 could improve the solidity and rigidity of the layer, reduce its internal stress, and increase the surface brightness; Stirring could improve the layer's uniformity; Active agent could guarantee the quality of layer surface; additives TN2 can improve the layer's rigidity, but an overdose will increases the brittleness, the amount should be controlled under 1g/L. temperature and stirring have a relative small effect on layer's phosphorus content; The Design Expert (Version7.1.6) numerical simulation found out that a reasonable amount of reducing agent, pH value and temperature selection could control the deposition rate to improve efficiency, also could control the layer's phosphorus content, to improve its plasticity and rigidity.The casting solution used in the experiment is simple in formulation, easy to maintain, also has a good stability, so it could meet the requirements of different mass production. According to the loading capacity as 1dm2/L, the current bellows spring production efficiency can about reach 100/L...