Patent DE-102007058225-A1 (DE)
Title: Producing heterogeneous grain-refining agent for metallic materials such as melt-admixture for the production of products by casting process, comprises introducing two fine-grain materials in a mixer, and introducing the air into the mixer
Inventor: FERKEL HANS
IPC: B22F1/18
Filed: 2007-12-03
Abstract: The method for producing a heterogeneous grain-refining agent for metallic materials such as melt-admixture for the production of products by casting process, comprises subjecting fine particles of a first fine-grain material, which has a high melting temperature than the melt and is provided as nucleating agent, with a metallic powder of a second fine-grain material to a common mechanical milling process in a mixer with mechanically moved mixer means until the fine particles of the first fine-grain material are moistened with the metallic powder of the second fine-grain material. The method for producing a heterogeneous grain-refining agent for metallic materials such as melt-admixture for the production of products by casting process, comprises subjecting fine particles of a first fine-grain material, which has a high melting temperature than the melt and is provided as nucleating agent, with a metallic powder of a second fine-grain material to a common mechanical milling process in a mixer with mechanically moved mixer means until the fine particles of the first fine-grain material are moistened with the metallic powder of the second fine-grain material, introducing the air into the mixer by a chemical inert protective gas or protective gas mixture, setting the mixer in a movement, stimulating the mixer for producing a relative high energy supply to the powder mixture to be milled, counting a pre-determined time duration, and stopping the mixer. The fine-grain materials introduced in the mixer stand to each other in a pre-determined mixing ratio. The first fine-grain material is non-metallic or metallic material with a high melting point than the melting point of the melt. The first non-metallic fine-grain material is a ceramic material. The ceramic material is non-oxidic or oxidic ceramic. The second fine-grain material is equal to the material of the melt or has equal or low melting point. The grain-refining agent is exposed to solidification in an additional process step by a pressing force effect. The pressing force effect is carried out in an extruded strand or in a pressing mold. The first fine-grain material acting as nucleating agent has a dimension of 1-10 mu m. The second fine-grain material has a dimension of 20-60 mu m. The energy supply to the particles of the milled mixture is mechanically carried out by the friction of the milled mixture due to the mixer movement. The control of the energy supply to the particles of the milled mixture is carried out by a movement speed setting or a rotational-speed setting and/or a movement speed control or a rotational-speed control of the mechanically moved mixer means of the mixer, and by a temperature setting and/or a temperature control. The pre-determined time duration of the mechanical and energetic effects on the mixture of the fine-grain materials in the order of magnitude is 5-30 minutes. The first and second fine-grain materials are selected, so that they step with one another in a chemical reaction. Independent claims are included for: (1) a grain-refining agent; (2) a cast-product; and (3) a dispersion material.