JP2005324281A - Blasting abrasives - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide abrasives having a long product life because of high repeated use frequency without damaging the surface of a polished material, making the most of polymer-like elastic property in spite of a single metallic material using superelastic property. <P>SOLUTION: In the blasting abrasives formed of powder of a shape memory alloy member with a primary average grain diameter of 0.05-3 mm exhibiting martensitic transformation, a member used as the shape memory alloy member is to exhibit a shape memory effect through solution annealing and quenching after crushing at least one alloy selected from CuAlNi alloy, CuZnAl alloy, FeMnSi alloy, CuAlMn alloy, CuAlNiTi alloy and CuAlNiMn alloy. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an abrasive for blasting, and more specifically, is used for polishing and deburring metal parts and resin parts, and for strong coating film peeling, and has excellent polishing performance and the surface of the material to be polished. The present invention relates to an abrasive that has a long product life because it is frequently used without being brazed.

  In recent years, there has been a growing demand for high performance, high precision, and high quality for various parts. In the fields of blast polishing and deburring, there are abrasives that can be polished and deburred without scratching the surface of the parts. is necessary.

  As a product that satisfies these requirements, an abrasive having an average primary particle size of about 0.1 to 3 mm in which inorganic powders such as metal, glass, diamond, and ceramics are dispersed in a soft polymer core has been proposed. Yes. These composite particles are hard inorganic powders on the surface of the composite particles without causing the surface to be scratched by elastically deforming and softening the impact when the soft polymer core collides with the material to be polished. Has the combined effect of polishing.

For example, Patent Document 1 proposes a projection material containing 10 to 200 parts by weight of metal or metal oxide particles with respect to 100 parts by weight of resin as a blasting material for the purpose of deburring. Stainless particles are mentioned. Patent Document 2 proposes an abrasive in which any or all of 3,000 to 10,000 mesh diamond, silicon carbide, and alumina are adhered to the surface of gelatin particles with water.
Japanese Patent Laid-Open No. 2000-127045 Patent No. 3376334

  However, the composite particles have a drawback that the inorganic powder on the particle surface is separated from the polymer core due to impact during blasting, and the polishing efficiency is lowered and at the same time the life of the abrasive is shortened. For this purpose, a method of re-adhering the separated inorganic particles to the polymer core is taken, but in this case, the polished particles are mixed in the abrasive and the performance of the abrasive is lowered and polished. An increase in cost is inevitable if particles are to be removed.

  The present invention uses the super-elastic property of shape memory alloy, and even a single metal material has the same elastic properties as a polymer, so the surface of the material to be polished is not scratched and the product is frequently used repeatedly. An abrasive having a long life is provided.

  The invention described in the claims of the present application lies in an abrasive for blasting, which is a powder of a shape memory alloy member having a primary average particle diameter of 0.05 to 3 mm in which martensitic transformation is expressed. The shape memory alloy member is made of CuAlNi alloy, CuZnAl alloy, FeMnSi alloy, CuAlMn alloy, CuAlNiTi alloy, and CuAlNiMn alloy, and then pulverized and heated for solution treatment and quenching. In addition, the shape memory alloy member is made by atomizing at least one alloy selected from CuAlNi alloy, CuZnAl alloy, FeMnSi alloy, CuAlMn alloy, CuAlNiTi alloy, and CuAlNiMn alloy. In this method, the powder is directly produced from the molten metal by the method, and this is heated to form a solution, followed by quenching to develop a shape memory effect.

  Shape memory alloys used as abrasives for blasting exhibit remarkable shape memory operations that occur accompanying martensitic transformation and reverse transformation, and also exhibit good superelasticity in the parent phase state of reverse transformation. Superelasticity has an elongation strain amount of several percent, and the elastic modulus is about the same as that of a polymer. For this reason, the use of a blasting abrasive prepared using a shape memory alloy in a superelastic state has the advantage that the surface of the object to be polished is less likely to be scratched. When colliding with the surface, the impacted portion is hardened because the impacted portion of the abrasive is work hardened. Therefore, it can be said that the shape memory alloy powder is an abrasive having both elastic performance and polishing performance despite being a single material.

  Examples of the material of the shape memory alloy used as the abrasive for blasting of the present invention include a TiNi-based alloy, a Cu-based alloy, and an Fe-based alloy. Among these, materials that can produce powder economically include Cu-based alloys and Fe-based alloy. Cu-based alloys include CuAlNi alloys, CuZnAl alloys, CuAlMn alloys, CuAlNiTi alloys, and CuAlNiMn alloys. Fe-based alloys are well known as FeMnSi alloys.

  Here, the composition of the alloy greatly affects the martensitic transformation temperature. In order for the abrasive to show superelasticity, it is necessary to set the components so that the martensite transformation temperature is equal to or lower than the operating temperature of the abrasive. The relationship between the composition of the above alloy system and the transformation temperature is You can use this because it is reported in For example, according to research by Miyazaki, Otsuka, etc., when Ni is fixed at 4% by weight in a CuAlNi alloy, the martensitic transformation temperature (Ms point) and the composition of Al are expressed by the following equations.

Y = −126X + 1759 (−100 <Y <100)
Here, Y is the martensitic transformation temperature (Ms point), and X is the composition of Al. Even when Ni cannot be fixed at 4% by weight, it can be utilized if the relationship between the martensite transformation temperature and the alloy composition is examined in advance.

Shape memory alloy powder is a powder obtained by pulverizing an ingot produced by melting a material, or a powder produced directly from a molten metal by atomizing method by spraying a molten metal and quenching and refining, for example, in water By quenching, the martensitic transformation can be developed to give shape memory performance. Specific methods of the atomizing method include a water atomizing method in which a material is dissolved and then dropped from the pores, and a high-pressure water jet is jetted against this flow, and a vacuum atomizing method in which the molten metal is jetted into a vacuum There is a gas atomizing method in which the molten material is dropped from the pores and ejected into the high-pressure gas.
The atomization method can produce powder without going through the pulverization process, so the manufacturing cost can be reduced. However, depending on the type and composition of the alloy element, the viscosity of the molten metal can be increased to produce the powder. It can be difficult. In such a case, the powder can be produced by a pulverization method.

  The average primary particle size of the shape memory alloy powder is suitably 0.05 to 3 mm, and if it is smaller than 0.05 mm, the polishing effect cannot be obtained, while if it exceeds 3 mm, the collision energy against the material to be polished increases. There is a risk that

Examples 1-2
Table 1 shows the material, particle size, and martensitic transformation temperature (Ms point) of the abrasive used in the examples and comparative examples. In Examples, an alloy ingot made of Cu-14 wt% Al-4 wt% Ni was produced in a high frequency melting furnace using 99.9% purity electrolytic copper and nickel and 99.99% purity aluminum. Chips were cut out from the ingot with a milling machine and pulverized with a vibration mill to produce powders having average primary particle sizes of 0.05 to 0.1 mm and 0.1 to 0.5 mm.

  Next, this powder was heated at 850 ° C. for 5 minutes for solution treatment, and quenched in cold water at about 10 ° C. to develop martensitic transformation. In order to confirm whether or not martensitic transformation actually occurred, the transformation temperature was measured by differential scanning calorimetry (DSC measurement). According to the above formula, the transformation temperature of Cu-14 wt% Al-4 wt% Ni is −5 ° C., whereas the measured value is slightly lower than that. However, it is clear that at the blast test temperature (23 ° C.), the transformation temperature is sufficiently low to be in a superelastic state.

  Bending test pieces were actually cut out from this alloy before pulverization, and the bending test was performed at room temperature (23 ° C) for the above-mentioned solution treatment and quenching that exhibited martensitic transformation and those that had not been treated. Carried out. As a result, the material exhibiting martensitic transformation maintained elastic deformation even when the amount of bending strain exceeded 5%, and a pattern of martensitic transformation induced by bending stress was confirmed on the surface of the test piece. On the other hand, in the case where the treatment was not performed, plastic deformation occurred at a bending strain amount of 1%, and no martensitic transformation could be confirmed.

Comparative Examples 1-4
Comparative Example 1 is the same material as in Example 1 and has an average primary particle size that has not been subjected to martensite transformation. Comparative Examples 2 to 3 are difficult to braze the surface of an iron material to be polished and have excellent polishing power. Possible commercial reduced iron powders and steel shots were used. In Comparative Example 4, 200 mesh atomized iron powder dispersed in polypropylene resin at a ratio of 20% by volume was used.

  Table 2 shows the results of tests conducted using the abrasives in Table 1. For evaluation, SUS304 test plate, S50C test plate and SKD test plate were blasted, and the center line average surface roughness Ra of the test plate was measured. Each test plate was prepared by finishing the centerline average surface roughness Ra to 0.1 μm in advance by paper finishing. The blasting conditions were a suction type air blast, a projection pressure of 0.4 Mpa, a projection distance of 10 cm, and a projection time of 1 minute. Next, the S50C test plate and the SKD test plate were heat treated to generate a strong black oxide film on the test plate surface. The test plate was blasted under the same conditions, and the polishing power was compared. Table 2 shows the results.

  As a result, the surface roughness of the example is small and the polishing force is equivalent to that of the comparative example 1, and the surface roughness of the example 1 is the smallest and the polishing force is excellent as compared with the comparative examples 2 to 4. Yes. Example 2 shows that the surface roughness is almost the same and the polishing power is excellent.

The abrasive for blasting according to the present invention can be suitably used for polishing and deburring metal parts, resin parts, etc., and for strong coating film peeling.

Claims (3)

  An abrasive for blasting, which is a powder of a shape memory alloy member having a primary average particle diameter of 0.05 to 3 mm in which martensitic transformation is manifested.   At least one kind of alloy selected from CuAlNi alloy, CuZnAl alloy, FeMnSi alloy, CuAlMn alloy, CuAlNiTi alloy, and CuAlNiMn alloy is pulverized as the above-mentioned shape memory alloy member, and then heated, solution treated, and quenched. The abrasive for blasting according to claim 1, which exhibits a shape memory effect. As the shape memory alloy member, at least one alloy selected from a CuAlNi alloy, a CuZnAl alloy, a FeMnSi alloy, a CuAlMn alloy, a CuAlNiTi alloy, and a CuAlNiMn alloy is directly powdered from a molten metal by an atomizing method, and this is heated. The blasting abrasive according to claim 1, wherein the blasting treatment is performed by solution treatment and quenching to develop a shape memory effect.