Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C21/00—Alloys based on aluminium
  • C22C21/003—Alloys based on aluminium containing at least 2.6% of one or more of the elements: tin, lead, antimony, bismuth, cadmium, and titanium
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C21/00—Alloys based on aluminium
  • C22C21/12—Alloys based on aluminium with copper as the next major constituent
  • C22C21/16—Alloys based on aluminium with copper as the next major constituent with magnesium
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C21/00—Alloys based on aluminium
  • C22C21/12—Alloys based on aluminium with copper as the next major constituent
  • C22C21/18—Alloys based on aluminium with copper as the next major constituent with zinc

Definitions

• the present invention relates to an aluminum alloy for cutting processing containing no Pb, and also related to an aluminum alloy worked article made of the aforementioned aluminum alloy.
• a step of disposing chips is required since continuous chips are generated during the cutting processing. Also required is a step of eliminating burrs which generate at corner portions of an article during the turning processing or at a periphery of drilled holes during the drill processing. Under the circumstances, it has been required to provide an aluminum alloy excellent in cutting processability and in breaking ability of chips which is capable of reducing generation of burrs.
• the present invention has the following structural features.
• An aluminum alloy for cutting processing the aluminum alloy consisting essentially of Cu: 1 to 6.5 mass%, Zn: 0.05 to 1 mass%, Bi: 0.1 to 1 mass%, Sn: 0.1 to 1 mass%, B: 100 mass ppm or less.
• the aluminum alloy for cutting processing as recited in the aforementioned Item (1) further including at least one element as a selective additional element selected from the group consisting of Fe: 0.05 to 1 mass%, Mg: 0.01 to 0.3 mass%. Si: 0.05 to 1 mass% and Ti: 0.01 to 0.5 mass%.
• the aluminum alloy for cutting processing as recited in the aforementioned Item (8) extremely excellent cutting processability can be obtained.
• the aluminum alloy worked article as recited in the aforementioned Item (9) since the article is made of the aluminum alloy for cutting processing as recited in any one of the aforementioned Items (1) to (8) , the article is excellent in cutting processability, mechanical characteristics and coating processability.
• the article is an extruded article excellent in cutting processability, mechanical characteristics and coating processability.
• the article is excellent in surface quality because of the excellent cutting processability of the material.
• the article is excellent in surface quality because of the uniformly formed anodic oxide coating.
• Cu, Zn, Bi, Sn and B are essential elements.
• Cu is an element dissolved as solid dispersion in the aluminum mother phase and also dispersed in the aluminum mother phase as a deposited material such as CuAl 2 created by combining with Al, which improves the mechanical characteristics of the alloy and enhances the cutting processability. Furthermore, the synergistic effects with effects of another solid dispersion type elements further enhance the aforementioned effects . If the content of Cu is less than 1 mass%, the aforementioned effects become poor. To the contrary, if the content exceeds 6.5 mass%, there is a possibility that the corrosion resistance deteriorates . Accordingly, the Cu content should fall within the range of 1 to 6.5 mass%. The preferable Cu content is 4 to 6 mass%.
• Zn is an element dissolved as solid dispersion in the aluminum mother phase and also dispersed in the aluminum mother phase as deposited material such as MgZn 2 created by combining with Mg, which improves the mechanical characteristics of the alloy and enhances the cutting processability. Furthermore, the synergistic effects with effects of another solid dispersion type elements further enhance the aforementioned effects. Furthermore, if the Zn content falls within the range specified by the present invention, the creation rate of an anodic oxide coating can be increased. As a result, the aluminum alloy according to the present invention can be preferably used as a product to be subjected to anodizing for the purpose of improving the corrosion resistance, the ornamentation, etc. If the Zn content is less than 0.05 mass%, the aforementioned effects become poor.
• the Zn content should fall within the range of 0.05 to 1 mass%.
• the preferable Zn content is 0.1 to 0.5 mass%. More preferably, the content exceeds 0.2 mass% but not larger than 0.5 mass%.
• Bi and Sn form a low melting Bi-Sn compound when Bi and Sn coexist, and the compound disperses in the alloy mother phase.
• the dispersed Bi-Sn compound is melted by heat generated during the cutting processing, resulting in fusion embrittlement of the chips, which enhances the chips breakability.
• the contents of these elements should fall within the range of Bi: 0.1 to 1 mass% and Sn: 0.1 to 1 mass%. If each content is less than the lower limit, the aforementioned effects become poor. To the contrary, if each content exceeds the upper limit, the casting characteristics deteriorate remarkably.
• the preferable Bi content and Sn content are Bi: 0.2 to 0.8 mass% and Sn: 0.2 to 0.8 mass%.
• B has an effect of improving the cutting processability of the alloy by fining the casting structure to thereby form fine crystallized objects.
• the aforementioned effects can be obtained by adding a small amount of B. If the B content exceeds 100 mass ppm, a tool life may deteriorate due to the abrasion or the breakage of the tool. Accordingly, the B content should be 100 mass ppm or less.
• the preferable B content is 3 to 10 mass ppm.
• any one or two or more of the elements selected from the group consisting of four (4) elements, Fe, Mg, Si and Ti, can be added to the basic compositions of the aluminum alloy containing the aforementioned five (5) essential elements.
• Fe can disperse Si, which is effective in breakability of chips, as a single particle since a relatively small amount of Fe can be combined with Si when Fe coexists with Si, which enables excellent breakability of the chips.
• Fe is an element inevitably contained in an aluminum alloy, if the Fe content falls within the range of 0.05 to 1 mass%, no special step for decreasing the Fe content is required since the content is an allowable amount for a normal manufacturing quality.
• An attempt to decrease the Fe content less than 0.05 mass% causes an increased cost. To the contrary, if the Fe content exceeds 1 mass%, a casting surface of a casting article such as a billet deteriorates, and the amount of the compounds with Si increases, causing decreased Si single particles , which in turn causes a deterioration of the breakability of chips.
• the preferable Fe amount is 0.05 to 0.5 mass%.
• Mg is an element dissolved as solid dispersion in the alloy mother phase and dispersed in the mother phase by combining with coexisting Cu or Si, which further improves the strength and the cutting processability of the aluminum alloy. If the Mg content is less than 0.01 mass%, the aforementioned effects become poor.
• the Mg content should be 0.01 to 0.3 mass%.
• the preferable Mg content is 0.01 to 0.1 mass%.
• Si except for an amount required to form a compound, is dispersed in the alloy mother phase as single particles since only a small amount of Si is dissolved into an aluminum, which enhances the strength and the cutting processability of the aluminum alloy. Especially, Si forms Mg 2 Si by the coexistence with Mg to increase the strength. Furthermore, dispersion of eutectic Si further enhances the aforementioned cutting processability improving effect. If the Si content is less than 0.05 mass%, the aforementioned effect becomes poor.
• the Si content should be 0.05 to 1 mass%.
• the preferable Si content is 0.05 to 0.5 mass%.
• Ti fines an ingot texture and forms fine crystallized objects by the recrystallization restrain effect, which improves the mechanical characteristics and the cutting processability of the aluminum alloy. Furthermore, Ti has an effect of improving the corrosion resistance. If the Ti content is less than 0.01 mass%, the recrystallization depression effect deteriorates, causing, for example, an easy formation of rough recrystallization grains on a surface of an extruded article, which destabilizes the chips breakability in the cross-sectional direction. Furthermore, if the Ti content is less than 0.01 mass%, mechanical characteristics improving ef ect and corrosion resistance improving effect become poor.
• the Ti content should fall within the range of 0.01 to 0.5 mass%.
• the preferable Ti content is 0.01 to 0.1 mass%.
• the remaining compositions of the aluminum alloy for cutting processing according to the present invention are, for example, inevitable impurities and Al.
• the aluminum alloy for cutting processing according to the present invention can be melted, cast into an ingot such as a slab or a billet, subjected to a surface cutting, soaking and then formed into a predetermined shape by plastic processing such as an extrusion or rolling by a common procedure.
• the heat treating, aging treating, washing, etc. , in the aforementioned steps can also be performed by a common procedure.
• the formed aluminum alloy material can be used widely as various products via cutting or anodizing processing as needed.
• optical equipment parts such as lens frames , lens spacing tubes (camera cones), camera tripod fixing screws, office automation equipment parts or electronics device parts such as flanges for magnet rolls, square nuts for connectors or external screw tubes.
• optical device parts can be manufactured by, for example, extruding an aluminum alloy ingot into a bar-shaped extruded article or an annular-shaped extruded article, then cutting off these extruded articles and subjecting to cutting operation and thereafter subjecting to anodizing treatment.
• the aluminum alloy worked article according to the present invention is an article obtained by forming the aforementioned aluminum alloy for cutting processing into a predetermined configuration, or further forming an anodic oxide coating thereon for the purpose of improving the corrosion resistance and ornamentation.
• the material alloy is excellent in mechanical characteristics, cutting processability and surface processing workability due to the chemical compositions , the aluminum alloy worked article can be preferably used as the aforementioned various applications .
• the aluminum alloy worked article can be obtained by forming the material alloy by any method. Examples include a cut article formed by cutting an extruded article or a raw material and a rolled article .
• the kind of material to be subjected to cutting processing is not limited to a specific one and can be any material such as an extruded material or a rolled material. At the time of cutting processing, generation of burrs can be suppressed, resulting in easy processing, which in turn results in a worked article with excellent surface quality.
• an anodic oxide coating can be formed on a surface by anodizing the worked article after the forming processing. Since the worked article is formed by material alloy excellent in coat processing workability, a uniform coating can be formed quickly. Thus, effects due to the coating formation such as an improvement of the corrosion resistance and/or the ornamentation can be obtained at the maximum, resulting in a worked article with excellent surface quality.
• the conditions of anodizing are not limited to specific ones, and any known method can be employed.
• the alloy Nos. Al to A21 according to the compositions of the present invention includes Cu, Zn, Bi, Sn, B and the balance being Al and impurities.
• the alloy Nos. A22 to A30 are comparative compositions.
• the aluminum alloys Nos. Al to A30 shown in Table 1 were used as casting materials , and extruding billets each having a diameter of 200 mm were cast by a common procedure and then subjected to a homogenizing treatment. Thereafter, the billets were extruded into bars each having a diameter of 30 mm.
• these bars were subjected to a solution treatment for 5 hours at 495 °C, and then subjected to water quenching. Then, these bars were drawn into 25 mm in diameter to thereby obtain T3 processedmaterials . Further, the obtained materials were subjected to artificial ageing processing for 14 hours at 130 ⁇ to thereby obtain T8 processed materials. These T8 processed materials were used as test pieces.
• Each test piece was subjected to wet cutting at cutting speed: 150m/min., feed rate: 0.2 mm/rev., cut depth: 1.0 mm. Then, the breakability of chips is examined by the number of chips/100 g, and the cutting processability was evaluated by the breakability of chips .
• Aluminum alloys having compositions Nos. BI to B26 shown in Table 2 were prepared.
• the alloy Nos. BI to Bll four optional elements (Fe, Mg, Si, Ti) are added to the basic compositions of alloy No. A3.
• the alloy Nos. B12 to B22 four optional elements are added to the basic compositions of alloy No. A19.
• the alloy Nos. B23 to B26 are comparative compositions. These aluminum alloys were used as casting materials, and test pieces were manufactured by the same method as the aforementioned test A. Then, on each test piece, mechanical characteristics, cutting processability, abrasion of a tool, corrosion resistance and coating processability were examined in the same method as Test A. Then, the results of the alloy Nos.
• the casting surface quality of the cast billet was poor, and the quality of the extruded test piece was also poor.
• the workability at the time of extrusion was poor, causing great difficulty to form.
• the abrasion of the cutting tool was heavy.
• the casting workability f the billet was poor, causing great difficulty to cast a billet.
• the aluminum alloy according to the present invention is excellent in cutting processability, mechanical characteristics and coating processability, and therefore the aluminum alloy can be widely used as materials for various aluminum articles . Furthermore, since the aluminum alloy does not contain Pb, it is recommended to use it from the view point of environmental conservation.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Extrusion Of Metal (AREA)
• Nonmetal Cutting Devices (AREA)
• Turning (AREA)
• Polishing Bodies And Polishing Tools (AREA)
• Conductive Materials (AREA)

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• 2003
  • 2003-10-09 AT AT03754054T patent/ATE440155T1/de not_active IP Right Cessation
  • 2003-10-09 DE DE60328902T patent/DE60328902D1/de not_active Expired - Lifetime
  • 2003-10-09 WO PCT/JP2003/012938 patent/WO2004033740A1/fr active Application Filing
  • 2003-10-09 US US10/530,484 patent/US20060108030A1/en not_active Abandoned
  • 2003-10-09 AU AU2003272094A patent/AU2003272094A1/en not_active Abandoned
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