200838631 * 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種以用作為燒結含油軸承等之粉末冶 金用原料粉之銅被覆鐵粉為主成分之粉末冶金用鐵-銅複合 粉末及其製造方法。 【先前技術】[Technical Field] The present invention relates to an iron-copper composite powder for powder metallurgy which is mainly composed of copper-coated iron powder as a raw material powder for powder metallurgy for sintering oil-impregnated bearings and the like. Its manufacturing method. [Prior Art]
以往，作為IT相關機器、車載用電氣設備等所使用之 燒結含油軸承等之粉末冶金用原料粉，係使用銅被覆鐵 粉。軸承之強度’主要由鐵負責該角色，而銅係負責耐蝕 性及耐磨耗性。最近，對於如此之鋼被覆鐵複合粉要求增 加銅的比率，增加耐磨耗性及耐蝕性。 此情況下，由於單純地增加銅的比率時，鐵的量會相 對地降低，故強度當然會降低。粉末冶金用原料之強度的 評價，一般係依環壓強度（Ring compression strength)的大 小來進行，而必須提昇該環壓強度。 就其他的問題而言，為了提昇粉末冶金用原料之成形 性或燒結性，必須提高視密度、及流動性。 就以往技術而言，專利文獻丨揭示將於鐵粉被覆銅之 t末事先機械加卫後進行燒結之方法。又，於專利文獻2 t:進-步混合銅粉於鐵表面被覆有銅之銅被覆鐵粉以 =銅之比率，並於分粒（sizing)時使鐵的表面露出，以提 幵機械強度及耐久性之技術。 工之特殊燒結方 然而，刖者係於燒結之前進行機械加 5 200838631 法，並非一般方法。又，後者於增加銅之量方面雖目的相 同，而鐵露出之表面部分之強度（推測主要為耐磨耗性）雖 可能增加’但無法謀求燒結體本身強度的提昇。 因此，雖曾嘗試以銅被覆鐵粉為基本成分，增加銅之 比率’但環壓強度之降低、燒結原料粉末之流動性及視密 度之降低等基本問題並未解決，而為不一定可滿足要求 者，是其現狀。 專利文獻1 :日本特開2002-348601號公報。 專利文獻2 :日本特開2001_279349號公報。 【發明内容】 本發明之課題在於，可得到一種以銅被覆鐵粉為主成 分之粉末冶金用複合粉及其製造方法，其於製造以燒結含 油軸承等用之銅被覆鐵粉為主成分之粉末冶金用原料粉之 際，可提昇燒結原料粉末之流動性及視密度、提昇環壓強 度等燒結特性、並減低成本。 本t月人等為了解決上述問題點，而得到於製造以 銅被覆鐵粉為主成分之粉末冶金用原料粉之際，可提昇燒 結原料粉末之流動性及視密度、並且提昇環壓強度等燒結 特性之知識。 ， 本1¾明’根據該知識，而提供 、1)-種以銅被覆鐵粉為主成分之粉末冶金用鐵，複合 知末’其特徵在於，銅被覆鐵粉之銅含量& 視密度為2·2〆以上、流動度為25s/5〇g以下。 6 200838631 2)—種以鋼被覆鐵粉為主成分之粉末冶金用鐵_鋼複合 私末’其特徵在於，銅被覆鐵粉與電解銅粉之混合粉末之 銅含$為45〜7〇wt%、視密度為22g/cm3以上、流動度為 25s/50g 以下。 )如上述1或2所§己載之以銅被覆鐵粉為主成分之粉 末冶金用鐵-鋼複合粉末，其燒結粉碎後之複合粉末之以 BET法所付之比表面積為〇.2m2/g以下。 4) 如上述1〜3中任一項所記載之以銅被覆鐵粉為主成 分之粉末冶金用鐵-銅複合粉末，其係由於銅被覆鐵粉或銅 被覆鐵粉與電解銅粉之混合粉末進一步混合有錫粉、石墨 粉及成形潤滑劑之粉末所構成。 5) 如上述4所㊂己載之以銅被覆鐵粉為主成分之粉末冶 金用鐵-銅複合粉末，其中，錫粉為3〇〜5〇wt〇/〇，石墨粉 及成形潤滑劑為1 .〇wt%以下。 6) 如上述1至5中任一項所記載之以銅被覆鐵粉為主 成分之粉末冶金用鐵-銅複合粉末，其係燒結含油軸承用粉 末。 本發明，又，提供 7) —種以銅被覆鐵粉為主成分之粉末冶金用鐵_銅複合 粉末之製造方法，其特徵在於，鍍銅於鐵粉以製造銅被覆 鐵粉’並製造銅含ϊ為45〜70wt%之鋼被覆鐵粉後，將該 銅被覆鐵粉於還原環境氣氛中，以6〇〇〜85〇 t：燒結20〜60 分鐘，再將該燒結體粉碎及篩選為_8〇網目。 8) —種以銅被覆鐵粉為主成分之粉末冶金用鐵-銅複合 7 200838631 粉末之製造方法，其特徵在於，鍍銅於鐵粉以製造銅被覆 鐵粉，並將電解銅粉混合於該銅被覆鐵粉，以製造銅含量 為45〜70wt%之混合粉末後，將該混合粉末於還原環境氣 氛中，以600〜850 C燒結20〜60分鐘，再將該燒結體粉碎 及篩選為-80網目。 9)如上述7或8所記載之以銅被覆鐵粉為主成分之粉 末冶金用鐵-銅複合粉末之製造方法，其燒結粉碎後之複合 粉末之以BET法所得之比表面積為〇.2m2/g以下。 1 0)如上述7至9中任一項所記載之以銅被覆鐵粉為主 成分之粉末冶金用鐵-銅複合粉末之製造方法，其於銅被覆 鐵粉及電解銅粉所構成之混合粉末進一步混合錫粉、石墨 粉及成形潤滑劑。 本發明之粉末冶金用複合粉末，藉由使用銅含量為 45〜70wt%、視密度為2.2g/cm3以上、流動度為25s/50g以 下之銅被覆粉末或銅被覆粉末與電解銅粉之混合粉末，可 得到能提高粉末之粉胚體密度（green desity)、流動性等成 形性’且提昇環壓強度等燒結特性，並減低成本之優異效 果0 【實施方式】 本發明之粉末冶金用複合粉末，係使用銅含量為 45〜70wt%、視密度為2.2g/cm3以上、流動度為25s/50g以 下之銅被覆粉末或銅被覆粉末與電解銅粉之混合粉末。鋼 含量為45〜70wt%之銅被覆粉末或銅被覆粉末與電解銅粉 8 200838631 之混合粉末的使用，具有可提高視密度及流動性、且提昇 環壓強度之優異效果。 當銅含量為45 wt%以下時，由於鐵的量增多，故表面 之銅層變薄’當作為軸承時，軸旋轉時銅層容易被刮削而 露出鐵，產生燒黏等使滑動特性降低。 另一方面，當為70wt。/。以上時，雖可製造，但鐵的量 >'’而原本目的之成本減低的效果減低。Conventionally, copper-coated iron powder is used as a raw material powder for powder metallurgy such as a sintered oil-impregnated bearing used in an IT-related machine or an in-vehicle electric device. The strength of the bearing is mainly responsible for the role of iron, while the copper system is responsible for corrosion resistance and wear resistance. Recently, it is required to increase the ratio of copper for such a steel-coated iron composite powder, and to increase wear resistance and corrosion resistance. In this case, since the ratio of iron is simply increased, the amount of iron is relatively lowered, so the strength is of course lowered. The evaluation of the strength of the raw material for powder metallurgy is generally carried out according to the size of the Ring compression strength, and the ring pressure strength must be increased. For other problems, in order to improve the formability or sinterability of the raw material for powder metallurgy, it is necessary to increase the apparent density and fluidity. As far as the prior art is concerned, the patent document discloses a method of sintering after the iron powder coated copper is mechanically reinforced in advance. Further, in Patent Document 2 t: the copper powder is coated with copper on the surface of the iron, and the copper-coated copper powder is coated with iron to a ratio of copper, and the surface of the iron is exposed during sizing to improve the mechanical strength. And durability technology. Special sintering of the workmanship However, it is not a general method to mechanically add 5 200838631 before sintering. Further, although the latter has the same purpose in increasing the amount of copper, the strength of the surface portion of the iron exposed (presumably mainly wear resistance) may increase, but the strength of the sintered body itself cannot be improved. Therefore, although attempts have been made to increase the ratio of copper by using copper-coated iron powder as a basic component, the basic problems such as a decrease in the ring-pressure strength, a decrease in the fluidity of the sintered raw material powder, and a decrease in apparent density have not been solved. The requester is the status quo. Patent Document 1: Japanese Laid-Open Patent Publication No. 2002-348601. Patent Document 2: Japanese Laid-Open Patent Publication No. 2001-279349. SUMMARY OF THE INVENTION An object of the present invention is to provide a powder metallurgy composite powder containing copper-coated iron powder as a main component and a method for producing the same, which are used for producing copper-coated iron powder for sintering oil-impregnated bearings and the like. When the raw material powder for powder metallurgy is used, the flowability and apparent density of the sintered raw material powder, the sintering characteristics such as the ring pressure strength, and the like can be improved, and the cost can be reduced. In order to solve the above problems, the present invention has been able to improve the fluidity and apparent density of the sintered raw material powder, and to improve the ring-pressure strength, etc., in the production of the raw material powder for powder metallurgy containing copper-coated iron powder as a main component. Knowledge of sintering characteristics. According to this knowledge, this product provides 1) a kind of powder metallurgy iron with copper-coated iron powder as the main component, and the composite knows that the copper content of copper-coated iron powder & visual density is 2·2〆 or more, and the fluidity is 25s/5〇g or less. 6 200838631 2)—A kind of powder metallurgy iron-steel composite private powder with steel coated iron powder as the main component is characterized in that the copper of the mixed powder of copper coated iron powder and electrolytic copper powder contains 45~7〇wt %, apparent density is 22 g/cm3 or more, and fluidity is 25 s/50 g or less. The iron-steel composite powder for powder metallurgy containing copper-coated iron powder as the main component of the above 1 or 2, the specific surface area of the composite powder after sintering and pulverization by the BET method is 〇.2m2/ g below. 4) The iron-copper composite powder for powder metallurgy containing copper-coated iron powder as a main component according to any one of the above 1 to 3, which is a mixture of copper-coated iron powder or copper-coated iron powder and electrolytic copper powder. The powder is further composed of a powder of tin powder, graphite powder and a forming lubricant. 5) The iron-copper composite powder for powder metallurgy containing copper-coated iron powder as the main component of the above four, wherein the tin powder is 3〇~5〇wt〇/〇, the graphite powder and the forming lubricant are 1. 〇wt% or less. (6) The iron-copper composite powder for powder metallurgy containing copper-coated iron powder as a main component according to any one of the above 1 to 5, which is a powder for sintering an oil-impregnated bearing. Further, the present invention provides a method for producing a powder-metallurgical iron-copper composite powder containing copper-coated iron powder as a main component, which is characterized in that copper is plated on iron powder to produce copper-coated iron powder 'and copper is produced. After the iron-coated iron powder containing 45 to 70% by weight of cerium is coated, the copper-coated iron powder is sintered in a reducing atmosphere at 6 〇〇 to 85 〇t: for 20 to 60 minutes, and then the sintered body is pulverized and sieved as _8〇 mesh. 8) an iron-copper composite for powder metallurgy mainly composed of copper-coated iron powder 7 200838631 A method for producing a powder, which is characterized in that copper is plated on iron powder to produce copper-coated iron powder, and electrolytic copper powder is mixed The copper is coated with iron powder to prepare a mixed powder having a copper content of 45 to 70% by weight, and then the mixed powder is sintered at 600 to 850 C for 20 to 60 minutes in a reducing atmosphere, and then the sintered body is pulverized and sieved as -80 mesh. (9) The method for producing a powder-metallurgical iron-copper composite powder comprising copper-coated iron powder as a main component according to the above 7 or 8, wherein the composite powder obtained by sintering and pulverizing has a specific surface area of 〇.2m2 by the BET method. /g below. The method for producing a powder-metallurgical iron-copper composite powder containing copper-coated iron powder as a main component according to any one of the above items 7 to 9, which comprises a mixture of copper-coated iron powder and electrolytic copper powder. The powder is further mixed with tin powder, graphite powder and a forming lubricant. The composite powder for powder metallurgy of the present invention is prepared by using a copper-coated powder or a copper-coated powder and an electrolytic copper powder having a copper content of 45 to 70% by weight, an apparent density of 2.2 g/cm3 or more, and a fluidity of 25 s/50 g or less. The powder can obtain an excellent effect of improving the sintering property such as greenness of the powder, formability of fluidity, and the like, and improving the ring-shaped strength and the like, and reducing the cost. [Embodiment] The composite of powder metallurgy of the present invention The powder is a copper-coated powder or a mixed powder of a copper-coated powder and an electrolytic copper powder having a copper content of 45 to 70% by weight, an apparent density of 2.2 g/cm3 or more, and a fluidity of 25 s/50 g or less. The use of a mixed powder of a copper-coated powder or a copper-coated powder having a steel content of 45 to 70% by weight and an electrolytic copper powder 8 200838631 has an excellent effect of improving the apparent density and fluidity and improving the ring-pressure strength. When the copper content is 45 wt% or less, since the amount of iron increases, the copper layer on the surface becomes thin. When used as a bearing, the copper layer is easily scraped to expose iron when the shaft rotates, causing burnt adhesion or the like to lower the sliding property. On the other hand, it is 70wt. /. In the above case, although the amount can be manufactured, the amount of iron >'' is reduced, and the effect of reducing the cost of the original purpose is reduced.
又，混合於銅被覆鐵粉中之銅粉，係使用粒度為·1〇〇 、、’罔目、視岔度為2.0〜2.2g/cm3之電解銅粉。 、即使以粉末冶金法所製造之零件中，燒結含油軸承亦 為燒結體内部殘留有孔洞（氣孔）之多孔質體，其與以使燒 結體内部之孔洞儘可能為零之方式所製造之機械零件為不 同的製品。 因此，作為燒結含油軸承之原料粉之特性係要求為可 成形為多孔質’⑴已成形之粉壓达具有至燒結製程為止不 破損程度之粉壓坯強度、（2)具有可容易充填粉末至金屬模 :的流動性。兩者之特性具有相反之面，$ 了提高粉壓述 強度，粉末形狀以如電解銅粉等不規則者為有利，但如此 之形狀’視密度會降低、流動性變差。相反的，如霧化銅 粉之圓形形狀’視密度高、流動性亦良好，但粉壓坯之強 度會降低。因此，視密度為2.2g/cm3以上為有效。 銅被覆鐵粉之製造，係使用以銅濃度為4〇土1〇§虬、硫 辰度為5〜10g/L、氣濃度為5〜1 〇mg/L兔| 士 g/1^為基本之鍍敷液。 於該鍍敫液投入必要量之還原鐵粉，藉由銅-鐵之取代反 9 200838631 應，鍛銅於該鐵粉。 精由投入辦：獻、、永山 *、、又敦/夜中之鋼量相對應之鐵粉，可製造具 〃銅5里之銅被膜鐵粉。於鍍敷後，進行水洗與防銹 處理並乾燥，網目除絲粉。 燒結處理，孫Αρη φ ，、將銅被覆鐵粉單獨、或將混合有銅被覆 :?、、Γ、'解：粉後將銅量調整為既定量之粉末置入燒結 I极通作為還原環境氣氛，以既定之燒結溫度加温、 呆、而製造成燒結體。之後，將由燒結爐取出之燒么士體， 以鍵磨型粉碎機等粉碎，將粉碎粉末u 8G網目之^除去 粗粉。 本專利發明之特徵在於，將銅被覆鐵粉單獨、或混合 f銅被覆鐵粉與電解鋼粉之粉末，進行燒結粉碎來製造。 :由燒結粉碎，可使比表面積為〇 2m2/g Μ下。若比表面 %為〇.2m2/g以上，則燒結體之環壓強度雖高，但形狀為 不規則、或粉末表面產生微小突起，流動性惡化。 • y關於燒結條件，當為600°C以下時，粉末之燒結不會 進^，無法得到所欲之視密度m當$ 85〇“ 上時，燒結雖進行，但燒結體變得過硬，故粉碎變得困難、 且粉碎時鐵粉表面之銅被膜的剝離增多，故不佳。、 保持時間，若愈長則燒結進行並且燒結體愈硬。若短 則燒結之進行不充分，而視密度會降低。若燒結溫度高即 ^呆持時間短，雖與低溫長時間燒結者可得同等之視密 度，但若提高燒結溫度則由能量成本及空氣冷卻所花 時間的關係來看並不佳。 、 200838631 所謂，網目，係指通過網孔8G網目⑽㈣之筛網 的、粉末，為除1 80,網目以上之粗粒子之意。隨著以複合 粉末為原料所製造之轴承的微小 f J似J化，師除粗粉之篩網目亦 可微細成1 00網目（1 50 // m、、1 h …〇em)、150 網目（1〇6#m)、2〇〇 網目 (75 // m) 〇Further, the copper powder mixed in the copper-coated iron powder is an electrolytic copper powder having a particle size of 1 〇〇, 罔 、, and a viewing temperature of 2.0 to 2.2 g/cm 3 . Even in the parts manufactured by the powder metallurgy method, the sintered oil-impregnated bearing is a porous body in which pores (pores) remain in the sintered body, and the machine is manufactured in such a manner that the pores inside the sintered body are as zero as possible. Parts are different products. Therefore, the characteristics of the raw material powder as the sintered oil-impregnated bearing are required to be formed into a porous '(1) formed powder pressure to have a crush strength which is not damaged until the sintering process, and (2) having an easily chargeable powder to Metal mold: fluidity. The characteristics of the two have the opposite side, and it is advantageous to increase the powder compaction strength, and the powder shape is advantageous in the case of irregularities such as electrolytic copper powder, but such a shape is reduced in apparent density and fluidity is deteriorated. Conversely, if the circular shape of the atomized copper powder is high in apparent density and fluidity, the strength of the green compact is lowered. Therefore, it is effective that the apparent density is 2.2 g/cm3 or more. The copper coated iron powder is manufactured using a copper concentration of 4 〇1〇§虬, a sulphur density of 5~10g/L, and a gas concentration of 5~1 〇mg/L rabbit | 士g/1^ Plating solution. The necessary amount of reduced iron powder is put into the rhodium plating solution, and the copper is replaced by copper-iron. Finely invested by the company: Xian, Yongshan *,, and the iron powder corresponding to the amount of steel in the night / night, can produce copper film iron powder with 5 copper. After plating, it is washed with water and rust-proofed and dried, and the mesh is removed. Sintering treatment, Sun Α ρη φ , copper coated iron powder alone, or mixed with copper coating: ?,, Γ, 'solution: after the powder, the amount of copper is adjusted to a certain amount of powder placed into the sintered I-pole as a reducing environment The atmosphere is heated and stayed at a predetermined sintering temperature to produce a sintered body. Thereafter, the burnt body taken out from the sintering furnace is pulverized by a key mill type pulverizer or the like, and the pulverized powder u 8G mesh is removed to remove the coarse powder. The present invention is characterized in that a copper-coated iron powder is used alone or in combination with a powder of copper-coated iron powder and electrolytic steel powder, which is sintered and pulverized. : Sintered by sintering, the specific surface area can be 〇 2m2 / g under the armpit. When the specific surface % is 〇.2 m 2 /g or more, the sintered body has a high ring pressure, but the shape is irregular, or fine protrusions are formed on the surface of the powder, and the fluidity is deteriorated. • y Regarding the sintering conditions, when the temperature is 600 ° C or less, the sintering of the powder does not proceed, and the desired apparent density m cannot be obtained. When the temperature is 85 Å, the sintering proceeds, but the sintered body becomes too hard. The pulverization becomes difficult, and the peeling of the copper film on the surface of the iron powder at the time of pulverization is increased, which is not preferable. The holding time is longer, the sintering proceeds and the sintered body becomes harder. If it is short, the sintering progress is insufficient, and the apparent density is small. If the sintering temperature is high, that is, the holding time is short, although the same as the low temperature sintering for a long time, the same apparent density can be obtained. However, if the sintering temperature is increased, the relationship between the energy cost and the time taken by the air cooling is not good. , 200838631 The term "mesh" refers to the powder passing through the mesh of the 8G mesh (10) (4) of the mesh, which is the meaning of the coarse particles above the mesh except for 180. The tiny f J of the bearing made with the composite powder as the raw material. Like J, the division of the screen can be finely divided into 100 mesh (1 50 // m, 1 h ... 〇em), 150 mesh (1 〇 6 #m), 2 〇〇 mesh (75 / / m) 〇
於銅被覆鐵粉或銅被覆鐵粉與電解銅粉之混合粉，亦 ^再混合㈣m及硬脂酸辞等固體潤滑劑之一種以 上以作成粉末。錫之添加，可發揮青銅粉之特性，而石墨 粉及硬脂酸辞等固體潤滑劑之使用，可有效地更提昇燒結 體之潤滑性。 於冰加錫米刀之十月％，混纟粉中之銅與錫#比作為燒結 軸承材-般為9:1左右，故以3.G〜5加t%為佳；於添加石 墨粉的情形，g lwt%以下為佳；於添加硬脂酸辞等固體 :滑劑的情形’以lwt%以下為佳。於添加固體潤滑劑的 j形，下限值亚热特別限制，視添加量可保有潤滑機能， 藉此，作為燒結含油軸承用粉末，可極有效地使用。 實施例 接著，說明本發明之實施例。又，本發明，並不受限 於以下所說明之例。亦即，於本發明之技術思想的範圍内， 包含所有實施例以外之樣態及變形。 (實施例1) 使用碟酸濃度7g/L·、氣濃度7ing/L、銅濃度40g/L之 I酸銅鍍敷液，投入-100網目之鐵粉，製造銅被覆鐵粉。 鋼被覆量為50wt%Cu。之後，將其於還原環境氣氛中以65〇 200838631 °C燒成3 0分鐘，並進行粉碎。 調查如此所製得之複合粉末之視密度、流動度、比表 面積。將結果示於表i。如表！所示，實施例i之鐵-鋼複 合粉末之視密度為2.23g/cm3、流動度為22 8s/5〇g、比表 面積為0.12m2/g，可得良好之鐵_銅複合粉末。 又使用該鐵β銅複合粉末，於該複合粉末添加錫粉 4wt%、石墨粉〇.5wt%、作為成形潤滑劑之硬脂酸鋅 (以額外數量計算）混合製得混合粉末，以該混合粉 末，以使㈣4 6.5gW的方式進行加壓成形，製作成内 徑lOmmx外徑i8mmx高度7mm之軸承型之粉壓坯（試驗 片）20個，將該粉壓坯於還原環境氣氛中以78〇。〇燒結3〇 刀知，凋查所得燒結體試驗片之燒結體密度之差異（標準偏 差）、％壓強度之差異（標準偏差）。將該結果示於表2。如 表2所示，得到燒結體密度之差異小、且環壓強度之差異 、亦小之良好結果。 又，將未添加錫粉、石墨粉之鋼被覆鐵粉，以與上述 相同之條件進行燒結時，由於未加入錫粉故未形成青銅合 金層，因此環壓強度有些許降低的傾向，但差異則得到大 致相同的結果。 12 200838631 [表i] 視密度(g/cm3) 流動度(s/50g) 比表面積(m2/g) 實施例1 2.23 22.3 0.12 實施例2 2.22 23.2 0.11 實施例3 2.27 23.0 0.09 實施例4 2.27 24.6 0.15 實施例5 2.28 23.7 0.14 實施例6 2.48 22.1 0.13 比較例1 1.83 31.6 0.56 比較例2 1.92 28.5 0.18 比較例3 2.38 34.7 0.67The copper-coated iron powder or the copper-coated iron powder and the electrolytic copper powder are mixed with one of the solid lubricants such as m and stearic acid to form a powder. The addition of tin can exert the characteristics of bronze powder, and the use of solid lubricants such as graphite powder and stearic acid can effectively improve the lubricity of the sintered body. In October, the ice and tin rice knife, the copper and tin in the mixed powder is about 9:1 as the sintered bearing material, so it is better to add 3.G~5 plus t%; In the case of g lwt% or less, it is preferable to add a solid such as a stearic acid: a slip agent is preferably 1 wt% or less. In the j-shape in which the solid lubricant is added, the sub-caloric value of the lower limit is particularly limited, and the lubricating function can be maintained depending on the amount of addition, whereby the powder for the sintered oil-impregnated bearing can be used extremely effectively. EXAMPLES Next, examples of the invention will be described. Further, the present invention is not limited to the examples described below. That is, all the forms and modifications other than the embodiments are included within the scope of the technical idea of the present invention. (Example 1) A copper-coated iron powder was prepared by using an I acid copper plating solution having a disc acid concentration of 7 g/L·, a gas concentration of 7 ing/L, and a copper concentration of 40 g/L, and introducing iron powder of -100 mesh. The steel coating amount was 50% by weight of Cu. Thereafter, it was baked at 65 〇 200838631 ° C for 30 minutes in a reducing atmosphere and pulverized. The apparent density, fluidity, and specific surface area of the composite powder thus obtained were investigated. The results are shown in Table i. Such as the table! As shown, the iron-steel composite powder of Example i had an apparent density of 2.23 g/cm3, a fluidity of 22 8 s/5 〇g, and a specific surface area of 0.12 m 2 /g, and a good iron-copper composite powder was obtained. Further, the iron β copper composite powder is used, and the mixed powder is mixed with 4% by weight of tin powder, 5% by weight of graphite powder, and zinc stearate as a forming lubricant (calculated in an additional amount) to prepare a mixed powder. The powder was subjected to press molding in a manner of (4) 4 6.5 gW to prepare 20 powder compacts (test pieces) of a bearing type having an inner diameter of 10 mm x an outer diameter of i8 mm and a height of 7 mm, and the compact was in a reducing atmosphere of 78. Hey. 〇Sintering 3〇 Knife, the difference in the density of the sintered body (standard deviation) and the % compressive strength (standard deviation) of the sintered compact test piece obtained. The results are shown in Table 2. As shown in Table 2, good results were obtained in which the difference in density of the sintered body was small and the difference in ring-pressure strength was small. In addition, when iron powder coated with tin powder or graphite powder is coated and sintered under the same conditions as above, since no bronze powder is added, a bronze alloy layer is not formed, and thus the ring crush strength tends to be somewhat lowered, but the difference is small. Then get roughly the same result. 12 200838631 [Table i] apparent density (g/cm3) fluidity (s/50g) specific surface area (m2/g) Example 1 2.23 22.3 0.12 Example 2 2.22 23.2 0.11 Example 3 2.27 23.0 0.09 Example 4 2.27 24.6 0.15 Example 5 2.28 23.7 0.14 Example 6 2.48 22.1 0.13 Comparative Example 1 1.83 31.6 0.56 Comparative Example 2 1.92 28.5 0.18 Comparative Example 3 2.38 34.7 0.67
[表2] 燒結體密度之 環壓強度之平均值 環壓強度之標準 標準偏差 偏差 實施例1 0.008 25.2 0.29 實施例2 0.007 25.9 0.25 實施例3 0.005 26.4 0.22 實施例4 0.005 27.3 0.19 實施例5 0.005 28.2 0.12 實施例6 0.005 30.7 0.10 比較例1 0.012 25.9 0.45 比較例2 0.015 25.3 0.50 比較例3 0.018 23.9 0.70 13 200838631 (實施例2) 使用硫酸派度7g/L、氣濃度7nig/L、鋼濃度40g/L之 硫酸銅鏡敷液，投入-100網目之鐵粉，製造鋼被覆鐵粉。 銅被覆量為50wt%Cu。之後，將其於還原環境氣氛中以7〇〇 C燒成30分鐘’並進行粉碎。調查如此所製得之鐵_銅複 合粉末之視密度（g/cm3)、流動度（s/5〇g)、比表面積（m2/g)。 將結果示於表1。 如表1所示，實施例2之鐵-銅複合粉末之視密度為 2.22g/cm3、流動度為23.2s/50g、比表面積為〇11111、，可 得良好之鐵-銅複合粉末。 又，使用該鐵-銅複合粉末，於該複合粉末添加錫粉 4wt%、石墨粉〇.5wt%、作為成形潤滑劑之硬脂酸鋅 O.Swt%(以額外數量計算）混合製得混合粉末，以該混合粉 末，以使密度為6.5g/cm3的方式進行加壓成形，製作成内 徑lOmmx外徑I8mmx高度7mm之軸承型之粉壓坯（試驗 片）20個，將談粉壓坯於還原環境氣氛中以78〇。〇燒結3〇 分鐘，調查所得燒結體試驗片之燒結體密度之差異（標準偏 差）、環壓強度之差異（標準偏差）。將該結果示於表2。如 表2所示，得到燒結體密度之差異小、且環壓強度之差異 亦小之良好結果。 又，將未添加錫粉、石墨粉之銅被覆鐵粉，以與上述 相同之ir、件進行燒結時，由於未加入錫粉故未形成青銅合 金層，因此環壓強度有些許降低的傾向，但差異則得到大 致相同的結果。 14 200838631 (實施例3) 使用硫酸濃度7g/L、氯濃度7mg/L、銅濃度40g/L之 硫酸銅艘敷液，投入-100網目之鐵粉，製造銅被覆鐵粉。 銅被覆量為50wt%Cu。之後，將其於還原環境氣氛中以75〇 °C燒成3 0分鐘，並進行粉碎。調查如此所製得之鐵_銅複 合粉末之視密度（g/cm3)、流動度（s/5〇g)、比表面積（m2/g)。 將結果示於表1。 如表1所示，實施例3之鐵_銅複合粉末之視密度為 2.27g/cm3、流動度為23.0s/50g、比表面積為〇.〇9m2/g，可 得良好之鐵-銅複合粉末。 又，使用該鐵-銅複合粉末，於該複合粉末添加錫粉 4wt%、石墨粉〇.5wt%、作為成形潤滑劑之硬脂酸鋅 〇.5wt%(以概數計）混合製得混合粉末，以該混合粉末，以 使密度為6.5g/cm3的方式進行加壓成形，製作成内徑ι〇_ X外徑18mmX高度7mm之軸承型之粉壓坯（試驗片）2〇個， 將該粉壓坯於還原環境氣氛中以78(rc燒結3〇分鐘，調查 所得燒結體試驗片之燒結體密度之差異（標準偏差卜環壓 強度之1異（標準偏差）。將該結果示於表2。如表2所示， 付到燒結體密度之差異小、且環壓強度之差異亦小之良好 胯禾添加錫粉、石墨粉之銅被覆鐵粉，以與上 相同之ii·、件進仃燒結時，由於未加人鍚粉故未形成青鋼^ 至自口此%、壓強度有些許降低的傾向，但差異 致相同的結果。 j大 15 200838631 (實施例4) 使用硫酸濃度7g/L、氯濃度7mg/L、銅濃度40g/L之 硫酸銅鍍敷液’投入-100網目之鐵粉，製造銅被覆鐵粉。 銅被覆量為30wt%Cu。將該銅被覆鐵粉與電解銅粉混合製 造成60wt%Cu之鐵-銅複合粉末。之後，將其於還原環境 氣氣中以650C燒成30分鐘，並進行粉碎。調查如此所製 得之鐵-銅複合粉末之視密度（g/cm3)、流動度（s/5〇g)、比表 面積（m2/g)。將結果示於表1。 # 如表1所示，實施例4之鐵-銅複合粉末之視密度為 2.27g/cm3、流動度為24.6s/50g、比表面積為〇.i5m2/g，可 得良好之鐵-銅複合粉末。 又，使用該鐵-銅複合粉末，於該複合粉末添加錫粉 4wt%、石墨粉〇.5〜％、作為成形潤滑劑之硬脂酸鋅 〇.5wt%(以概數計）混合製得混合粉末，以該混合粉末，以 使密度為6.5g/cm3的方式進行加壓成形，製作成内徑⑺❿拉 X外徑18mmx高度7mm之軸承型之粉壓坯（試驗片）2〇個， _ 將該粉壓链於還原環境氣氛中以780°C燒結30分鐘，調查 所传燒結體試驗片之燒結體密度之差異（標準偏差）、環壓 強度之差異（標準偏差）。將該結果示於表2。如表2所^， 传到燒結體密度之差異小、且環壓強度之差異亦小之 結果。 义 將未、V加錫粉、石墨粉之銅被覆鐵粉，以與上述 相同之條件燒結時，由去 ' 由於未加入錫叔故未开》成青銅合金 層，因此環壓強度有此耸阢你^ ^ ° 又,4卉降低的傾向，但差異則得到大致 16 200838631 相同的結果。 (實施例5) 使用硫酸濃度7g/L、氯濃度7mg/L、銅濃度40g/L之 硫酸銅鍍敷液，投入-100網目之鐵粉，製造銅被覆鐵粉。 銅被覆量為30wt%Cu。將該銅被覆鐵粉與電解銅粉混合製 造成60wt%Cu之鐵-銅複合粉末。之後，將其於還原環境 氣氛中以750°C燒成30分鐘，並進行粉碎。調查如此所製 得之鐵-銅複合粉末之視密度（g/cm3)、流動度（s/50g)、比表 面積（m2/g)。將結果示於表1。 如表1所示，實施例5之鐵-銅複合粉末之視密度為 2.28g/cm3、流動度為23.7s/50g、比表面積為0.14m2/g，可 得良好之鐵·銅複合粉末。 又’使用該鐵-銅複合粉末，於該複合粉末添加錫粉 4wt%、石墨粉〇 5wt%、作為成形潤滑劑之硬脂酸鋅 〇.5wt%(以概數計）混合製得混合粉末，以該混合粉末，以 使检度為6.5g/cm3的方式進行加壓成形，製作成内徑1〇nim X外仏18mmx鬲度7mm之軸承型之粉壓坯（試驗片）2〇個， 將4物壓埋於還原環境氣氛中以78〇〇c燒結3〇分鐘，調查 所仔燒結體忒驗片之燒結體密度之差異（標準偏差）、環壓 2度之差異（標準偏差）。將該結果示於表2。如表2所示， 得到燒結體密度之# ^ ^ ^ ^ 又ϋ異小、且環壓強度之差異亦小之良好 結果° y 另字 ^ σ錫粉、石墨粉之銅被覆鐵粉，以與上述 相同之條件進行捧纟士 &〜¥，由於未加入錫粉故未形成青銅合 17 200838631 金層，因此環壓強度有些許降低的傾向，但差異則得到A 致相同的結果。 (實施例6) 使用硫酸》辰度7g/L、氣？辰度7mg/L、銅濃度4〇g/L之 硫酸銅鍍敷液’投入-100網目之鐵粉，製造銅被覆鐵粉。 銅被覆量為30wt%Cii。將該銅被覆鐵粉與電解銅粉混合製 造成60wt%Cu之鐵-銅複合粉末。之後，將其於還原環境 氣氛中以800 C燒成30分鐘，並進行粉碎。調查如此所製 得之鐵-銅複合粉末之視密度（g/cm3)、流動度（s/5〇g)、比表 面積（m2/g)。將結果示於表i。 如表1所示，實施例6之鐵_銅複合粉末之視密度為 2.48g/cm3、流動度為22.ls/5〇g、比表面積為〇 i3m2/g，可 得良好之鐵-銅複合粉末。 又，使用該鐵_銅複合粉末，於該複合粉末添加錫粉 4wt/〇、石墨粉〇.5wt%、作為成形潤滑劑之硬脂酸辞 〇.5Wt%(以概數計）混合製得混合粉末，以該混合粉末，以 使密度為6.5g/cm3的方式進行加壓成形，製作成内徑ι〇_ X外徑18mmx高度7mm之軸承型之粉壓坯（試驗片）2()個， 將該粉壓坯於還原環境氣氛中以78(TC燒結30分鐘，調查 所得燒結體試驗片之燒結體密度之差異（標準偏差卜環壓 強度之差兴（標準偏差）。將該結果示於表2。如表2所示， 得到燒結體密度之差異小、且環壓強度之差異亦小之良好 結果° 又，將未添加錫粉、石墨粉之銅被覆鐵粉，以與上述 18 200838631 相同之條件進行燒結時，由於未加入錫粉故未形成青銅合 金層’因此環壓強度有些許降低的傾向，但差異則得到大 致相同的結果。 (比較例1) 使用硫酸濃度7g/L、氯濃度7mg/L、銅濃度40g/L之 硫酸銅鐘敷液，投入-100網目之鐵粉，製造銅被覆鐵粉。 銅被覆量為50wt%Cu。調查如此所製得之鐵-銅複合粉末 之視密度（g/cm3)、流動度（s/50g)、比表面積（m2/g)。將結 果不於表1。 如表1所示，比較例1之鐵-銅複合粉末之視密度為 1.83g/cm3、流動度為316s/5〇g、比表面積為〇 56m2/g，得 到特性差之鐵-銅複合粉末。 又，使用該鐵-銅複合粉末，於該複合粉末添加錫粉 4wt%、石墨粉0 5wt%、作為成形潤滑劑之硬脂酸鋅 〇.5wt%(以概數計）混合製得混合粉末，以該混合粉末，以 使密度為6.5g/cm3的方式進行加壓成形，製作成内徑1〇mm X外徑18mmx!^度7mm之軸承型之粉壓述（試驗片）2〇個， 將該粉壓坯於還原環境氣氛中以780°C燒結3〇分鐘，調查 所％燒結體試驗片之燒結體密度之差異（標準偏差）、環壓 強度之差異（標準偏差）。將該結果示於表2。如表2所示， 燒結體密度之差異大、且環壓強度之差異亦大，皆得到特 性差之結果。 又，將未添加錫粉、石墨粉之銅被覆鐵粉，以與上述 相同之條件進行燒結時，由於未加入錫粉故未形成青銅合 19 200838631 金層，因此環壓強度有些許降低的傾向，但差異則得到大 致相同的結果。 (比較例2) 使用硫酸濃度7§几、氯濃度7mg/L、銅濃度4〇g/L之 硫酸銅鍍敷液’投入-100網目之鐵粉，製造銅被覆鐵粉。 銅被覆量為30wt%Cu。之後，將其於還原環境氣氛中以65〇 °C燒成30分鐘，並進行粉碎。調查如此所製得之鐵_銅複 合粉末之視密度（g/cm3)、流動度（s/50g)、比表面積加2^)。 將結果示於表1。 如表1所示，比較例2之鐵-銅複合粉末之視密度為 1.92g/cm3、流動度為28.5s/5〇g、比表面積為〇i8m2/g，得 到特性差之鐵-銅複合粉末。 又，使用该鐵-銅複合粉末，於該複合粉末添加錫粉 4wt%、石墨粉05_%、作為成形潤滑劑之硬脂酸鋅 〇.5wt%(以概數計）混合製得混合粉末，以該混合粉末，以 瞻使密度為6.5g/cm3的方式進行加壓成形，製作成内徑1〇mm X外徑18mmx高度7mm之轴承型之粉壓坯（試驗片）2〇個， 將該粉壓埋於還原環境氣氛中以780°C燒結30分鐘，調查 所彳于燒結體試驗片之燒結體密度之差異（標準偏差）、環壓 5虫度之差異（標準偏差）。將該結果示於表2。 如表2所示，燒結體密度之差異大、且環壓強度之差 異亦大，皆得到特性差之結果。 又’將未添加錫粉、石墨粉之銅被覆鐵粉，以與上述 ^ 仏件進行燒結時，由於未加入錫粉故未形成青銅合 20 200838631 金層’因此環壓強度有些許降低的傾向，但差異則得到大 致相同的結果。 (比較例3) 使用硫酸濃度7g/L、氯濃度7mg/L、銅濃度4〇g/L之 硫酸銅鍍敷液，投入-100網目之鐵粉，製造銅被覆鐵粉。 銅被覆量為40wt%Cu。將該銅被覆鐵粉與霧化銅粉混合製 造成60wt%Cu之鐵-銅複合粉末。調查如此所製得之鐵_鋼 複合粉末之視密度（g/cm3)、流動度（s/5〇g)、比表面積 (m2/g)。將結果示於表1。 ' 如表1所示，比較例3之鐵-銅複合粉末之視密度為 2.38g/cm3、流動度為34 7s/5〇g、比表面積為〇 67m2/g，得 到特性差之鐵-銅複合粉末。 又’使用該鐵-銅複合粉末，於該複合粉末添加錫粉 4wt%、石墨粉〇 5wt%、作為成形潤滑劑之硬脂酸鋅 0.5wt/〇(以概數計）混合製得混合粉末，以該混合粉末，以 使密度為6.5g/cm3的方式進行加壓成形，製作成内徑1〇mm X外徑18mmx高度7mm之軸承型之粉壓坯（試驗片）20個， 將該粉壓述於還原環境氣氛中以780X：燒結30分鐘，調查 所传燒結體試驗片之燒結體密度之差異（標準偏差）、環壓 強度之差異（標準偏差）。將該結果示於表2。 如表2所示’燒結體密度之差異大、且環壓強度之差 異亦大，皆得到特性差之結果。 又’將未添加錫粉、石墨粉之銅被覆鐵粉，以與上述 相同之條件進行燒結時，由於未加入錫粉故未形成青銅合 21 200838631 金層，因此環壓強度有些許降低的傾向，但差異則得到 致相同的結果。 九 如上所示，比較例，粉末特性之視密度為最低 1.83g/cm3、流動度為最高34.7s/5〇g，成形性差。又，燒姓 體密度之差異大、且環壓強度之差異亦大，特性皆差。 未添加錫粉、石墨粉之情況下亦顯示同樣差之特性。 相對於此，關於本實施例，粉末特性之視密度提昇為 2.2g/cm3以上、流動度提昇為25s/50g以下。又，燒結體 雄、度之差異小、且環壓強度之差異亦小，特性皆良好。又 未添加錫粉、石墨粉之情況下，亦為同樣良好之特性。 如以上所示，本發明之粉末冶金用複合粉末，藉由使 用鋼含量為45〜70wt%、視密度為2.2g/cm3以上、流動度 為25s/5 0g以下之銅被覆鐵粉或銅被覆鐵粉與電解銅粉之 違合粉末’可得到能提高粉末之粉胚體密度、流動性等成 $ 1*生’且提昇環壓強度等燒結特性，並減低成本之優異效 Φ 果’故適用於銅被覆鐵粉系燒結含油軸承等。 【圖式簡單說明】 (無） 【主要元件符號說明】 (無） 22[Table 2] Average value of ring-pressure strength of sintered body density Standard standard deviation of ring-pressing strength Example 1 0.008 25.2 0.29 Example 2 0.007 25.9 0.25 Example 3 0.005 26.4 0.22 Example 4 0.005 27.3 0.19 Example 5 0.005 28.2 0.12 Example 6 0.005 30.7 0.10 Comparative Example 1 0.012 25.9 0.45 Comparative Example 2 0.015 25.3 0.50 Comparative Example 3 0.018 23.9 0.70 13 200838631 (Example 2) Using sulfuric acid pitch 7 g/L, gas concentration 7 nig/L, steel concentration 40 g /L copper sulfate mirror solution, iron powder of -100 mesh, to produce steel coated iron powder. The amount of copper coating was 50 wt% Cu. Thereafter, it was baked at 7 〇〇C for 30 minutes in a reducing atmosphere and pulverized. The apparent density (g/cm3), fluidity (s/5〇g), and specific surface area (m2/g) of the iron-copper composite powder thus obtained were investigated. The results are shown in Table 1. As shown in Table 1, the iron-copper composite powder of Example 2 had an apparent density of 2.22 g/cm3, a fluidity of 23.2 s/50 g, and a specific surface area of 〇11111, and a good iron-copper composite powder was obtained. Further, using the iron-copper composite powder, the composite powder is mixed with 4% by weight of tin powder, 5% by weight of graphite powder, and 0.3% by weight of zinc stearate as a forming lubricant (calculated in an additional amount) to prepare a mixture. The powder was subjected to press molding at a density of 6.5 g/cm 3 to prepare a powder compact (test piece) of a bearing type having an inner diameter of 10 mm x an outer diameter of I8 mm x a height of 7 mm. The billet was 78 于 in a reducing ambient atmosphere. The tantalum was sintered for 3 minutes, and the difference (standard deviation) of the sintered body density and the difference in the ring pressure strength (standard deviation) of the obtained sintered body test piece were investigated. The results are shown in Table 2. As shown in Table 2, a good result was obtained in which the difference in density of the sintered body was small and the difference in ring pressure strength was small. In addition, when the iron-coated iron powder to which the tin powder and the graphite powder are not added is sintered in the same manner as the above-mentioned ir, the bronze alloy layer is not formed because the tin powder is not added, and thus the ring-pressure strength tends to be somewhat lowered. But the difference is roughly the same result. 14 200838631 (Example 3) A copper sulfate coating liquid having a sulfuric acid concentration of 7 g/L, a chlorine concentration of 7 mg/L, and a copper concentration of 40 g/L was used, and iron powder of -100 mesh was charged to produce copper-coated iron powder. The amount of copper coating was 50 wt% Cu. Thereafter, it was baked at 75 ° C for 30 minutes in a reducing atmosphere and pulverized. The apparent density (g/cm3), fluidity (s/5〇g), and specific surface area (m2/g) of the iron-copper composite powder thus obtained were investigated. The results are shown in Table 1. As shown in Table 1, the iron-copper composite powder of Example 3 had an apparent density of 2.27 g/cm3, a fluidity of 23.0 s/50 g, and a specific surface area of 〇.〇9 m 2 /g, and a good iron-copper composite was obtained. powder. Further, using the iron-copper composite powder, the composite powder is mixed with 4% by weight of tin powder, 5% by weight of graphite powder, and 5 wt% of zinc stearate as a forming lubricant (in approximate terms) to prepare a mixture. The powder was subjected to press molding so as to have a density of 6.5 g/cm 3 to prepare a powder type compact (test piece) of a bearing type having an inner diameter 〇 _ X outer diameter of 18 mm and a height of 7 mm. The compact was sintered at 78 (rc for 3 minutes in a reducing atmosphere), and the difference in sintered body density of the obtained sintered compact test piece (standard deviation of the standard deviation of the ring pressure strength (standard deviation)) was examined. As shown in Table 2, as shown in Table 2, the difference in the density of the sintered body is small, and the difference in the ring pressure strength is also small, and the copper-coated iron powder of the tin powder and the graphite powder is added, which is the same as the above. When the material is sintered, the green steel is not formed, and the pressure is slightly reduced from the mouth, but the difference is the same. jda 15 200838631 (Example 4) Copper sulfate plating solution with sulfuric acid concentration of 7g/L, chlorine concentration of 7mg/L, copper concentration of 40g/L Copper powder coated copper powder. The copper coating amount is 30wt% Cu. The copper coated iron powder is mixed with electrolytic copper powder to form a 60wt% Cu iron-copper composite powder. The gas was fired at 650 C for 30 minutes and pulverized. The apparent density (g/cm 3 ), fluidity (s/5 〇 g), specific surface area (m 2 /g) of the iron-copper composite powder thus obtained were investigated. The results are shown in Table 1. # As shown in Table 1, the iron-copper composite powder of Example 4 had an apparent density of 2.27 g/cm3, a fluidity of 24.6 s/50 g, and a specific surface area of 〇.i5 m2/g. A good iron-copper composite powder can be obtained. Further, the iron-copper composite powder is used, and 4% by weight of tin powder, graphite powder 〇5~%, and zinc stearate as a forming lubricant are added to the composite powder. % (in terms of a rough amount) was mixed to prepare a mixed powder, and the mixed powder was subjected to pressure molding so as to have a density of 6.5 g/cm 3 to prepare a bearing type powder having an inner diameter (7), a pull outer diameter, an outer diameter of 18 mm, and a height of 7 mm. 2 blanks (test piece), _ The powder was pressed at 780 ° C for 30 minutes in a reducing atmosphere, and the sintered test piece was burned. The difference in body density (standard deviation) and the difference in ring pressure strength (standard deviation). The results are shown in Table 2. As shown in Table 2, the difference in density of sintered bodies is small, and the difference in ring pressure strength is also small. As a result, the copper coated iron powder of the V-plus tin powder and the graphite powder is sintered under the same conditions as above, and is formed into a bronze alloy layer by the fact that it is not opened because no tin is added. There is a tendency to sway you ^ ^ ° again, 4 plants lower, but the difference is roughly the same result as 16 200838631. (Example 5) Copper-coated iron powder was produced by using a copper sulfate plating solution having a sulfuric acid concentration of 7 g/L, a chlorine concentration of 7 mg/L, and a copper concentration of 40 g/L to produce a copper-coated iron powder. The amount of copper coating was 30 wt% Cu. The copper-coated iron powder and the electrolytic copper powder were mixed to form a 60 wt% Cu iron-copper composite powder. Thereafter, it was baked at 750 ° C for 30 minutes in a reducing atmosphere and pulverized. The apparent density (g/cm3), fluidity (s/50 g), and specific surface area (m2/g) of the iron-copper composite powder thus obtained were investigated. The results are shown in Table 1. As shown in Table 1, the iron-copper composite powder of Example 5 had an apparent density of 2.28 g/cm3, a fluidity of 23.7 s/50 g, and a specific surface area of 0.14 m2/g, and a good iron-copper composite powder was obtained. Further, the iron-copper composite powder is used, and 4% by weight of tin powder, 5 wt% of graphite powder, and zinc stearate 〇5 wt% (in approximate terms) as a forming lubricant are added to the composite powder to prepare a mixed powder. The mixed powder was subjected to press molding so as to have a degree of detection of 6.5 g/cm 3 to prepare a bearing compact (test piece) having an inner diameter of 1 〇nim X outer diameter of 18 mm x 7 mm and a diameter of 7 mm. 4 materials were embedded in a reducing atmosphere and sintered at 78 ° C for 3 minutes. The difference in the density of the sintered body (standard deviation) and the difference in ring pressure of 2 degrees (standard deviation) were investigated. . The results are shown in Table 2. As shown in Table 2, a good result is obtained that the density of the sintered body is # ^ ^ ^ ^ and the difference is small, and the difference in the ring pressure strength is small. y Another word ^ σ tin powder, copper powder coated with graphite powder, Under the same conditions as above, the gentleman &~¥, because no tin powder was added, the bronze layer 17 200838631 gold layer was not formed, so the ring pressure strength tends to decrease slightly, but the difference gives the same result. (Example 6) Using sulfuric acid, the degree of 7 g/L, gas? A copper sulfate plating solution having a density of 7 mg/L and a copper concentration of 4 〇g/L was put into an iron powder of -100 mesh to produce a copper-coated iron powder. The amount of copper coating was 30 wt% Cii. The copper-coated iron powder and the electrolytic copper powder were mixed to form a 60 wt% Cu iron-copper composite powder. Thereafter, it was baked at 800 C for 30 minutes in a reducing atmosphere and pulverized. The apparent density (g/cm3), fluidity (s/5〇g), and specific surface area (m2/g) of the iron-copper composite powder thus obtained were investigated. The results are shown in Table i. As shown in Table 1, the iron-copper composite powder of Example 6 had an apparent density of 2.48 g/cm3, a fluidity of 22.ls/5 〇g, and a specific surface area of 〇i3 m2/g, and a good iron-copper was obtained. Composite powder. Further, the iron-copper composite powder is used, and the composite powder is prepared by mixing tin powder 4wt/〇, graphite powder 〇5wt%, and stearic acid hydrazine as a forming lubricant. 5Wt% (in approximate terms). The mixed powder was subjected to press molding so as to have a density of 6.5 g/cm 3 to prepare a bearing type green compact (test piece) 2 () having an inner diameter 〇 _ X outer diameter of 18 mm x a height of 7 mm. The compact was sintered at 78 (TC for 30 minutes) in a reducing atmosphere, and the difference in the sintered body density of the obtained sintered compact test piece (the difference in standard deviation of the ring pressure strength (standard deviation)) was investigated. It is shown in Table 2. As shown in Table 2, the difference in the density of the sintered body is small, and the difference in the ring pressure strength is also small. Further, the copper powder coated with the tin powder and the graphite powder is coated with the iron powder. 18 200838631 When sintering is performed under the same conditions, since the bronze alloy layer is not formed without adding tin powder, the ring-pressure strength tends to decrease slightly, but the difference is almost the same. (Comparative Example 1) Sulfuric acid concentration of 7 g/ L, sulfuric acid concentration of 7mg / L, copper concentration of 40g / L of sulfuric acid The bell powder was poured into iron powder of -100 mesh to produce copper-coated iron powder. The amount of copper coating was 50 wt% Cu. The apparent density (g/cm3) and fluidity (s) of the iron-copper composite powder thus obtained were investigated. /50 g), specific surface area (m2/g). The results are not shown in Table 1. As shown in Table 1, the iron-copper composite powder of Comparative Example 1 had an apparent density of 1.83 g/cm3 and a fluidity of 316 s/5. g, a specific surface area of 〇56 m 2 / g, to obtain a poorly-characterized iron-copper composite powder. Further, the iron-copper composite powder is used, and 4% by weight of tin powder and 5% by weight of graphite powder are added to the composite powder as a forming lubricant. The zinc stearate 〇 5 wt% (in approximate terms) was mixed to prepare a mixed powder, and the mixed powder was subjected to pressure molding so as to have a density of 6.5 g/cm 3 to prepare an inner diameter of 1 〇 mm X . Two pieces of powder type (test piece) of a bearing type of 18 mmx, and a degree of 7 mm were sintered, and the pressed compact was sintered at 780 ° C for 3 minutes in a reducing atmosphere, and the sintered body of the % sintered body test piece was investigated. The difference in density (standard deviation) and the difference in ring pressure strength (standard deviation). The results are shown in Table 2. As shown in Table 2, the difference in density of sintered bodies The difference between the large and the ring-shaped strength is also large, and the result is poor. In addition, when the iron-coated iron powder to which the tin powder and the graphite powder are not added is sintered under the same conditions as above, since the tin powder is not added, The bronze layer 19 200838631 was not formed, so the ring pressure strength tends to decrease slightly, but the difference is roughly the same. (Comparative Example 2) The sulfuric acid concentration is 7 §, the chlorine concentration is 7 mg/L, and the copper concentration is 4 〇. The copper/copper plating solution of g/L was put into the iron powder of 100 mesh to produce copper-coated iron powder. The amount of copper coating was 30 wt% Cu. Thereafter, it was baked at 65 ° C for 30 minutes in a reducing atmosphere and pulverized. The apparent density (g/cm3), fluidity (s/50g), and specific surface area of the iron-copper composite powder thus obtained were investigated. The results are shown in Table 1. As shown in Table 1, the iron-copper composite powder of Comparative Example 2 had an apparent density of 1.92 g/cm3, a fluidity of 28.5 s/5 〇g, and a specific surface area of 〇i8 m2/g, and obtained an iron-copper composite having poor characteristics. powder. Further, the iron-copper composite powder is used, and the mixed powder is prepared by mixing 4 wt% of tin powder, 05% of graphite powder, and 5 wt% of zinc stearate as a forming lubricant (in approximate terms). The mixed powder was subjected to pressure molding so as to have a density of 6.5 g/cm 3 to prepare a bearing compact (test piece) having an inner diameter of 1 mm, an outer diameter of 18 mm, and a height of 7 mm. The powder pressure was immersed in a reducing atmosphere at 780 ° C for 30 minutes, and the difference (standard deviation) between the sintered body density of the sintered body test piece and the difference (standard deviation) of the ring pressure 5 insect degree was investigated. The results are shown in Table 2. As shown in Table 2, the difference in the density of the sintered body was large, and the difference in the ring-pressure strength was also large, and the results were poor. In addition, when the iron powder coated with tin powder and graphite powder is not sintered, the bronze powder is not formed because the tin powder is not added, so the copper layer is not formed. , but the difference is roughly the same result. (Comparative Example 3) Copper-coated iron powder was produced by using a copper sulfate plating solution having a sulfuric acid concentration of 7 g/L, a chlorine concentration of 7 mg/L, and a copper concentration of 4 〇g/L. The amount of copper coating was 40 wt% Cu. The copper-coated iron powder was mixed with atomized copper powder to form a 60 wt% Cu iron-copper composite powder. The apparent density (g/cm3), fluidity (s/5〇g), and specific surface area (m2/g) of the iron-steel composite powder thus obtained were investigated. The results are shown in Table 1. As shown in Table 1, the iron-copper composite powder of Comparative Example 3 had an apparent density of 2.38 g/cm3, a fluidity of 34 7 s/5 〇g, and a specific surface area of 〇67 m 2 /g, and obtained iron-copper having poor characteristics. Composite powder. Further, the iron-copper composite powder was used, and 4% by weight of tin powder, 5 wt% of graphite powder, and 0.5 wt/〇 of zinc stearate as a forming lubricant (in approximate numbers) were added to the composite powder to prepare a mixed powder. 20 pieces of bearing type green compacts (test pieces) having an inner diameter of 1 mm, an outer diameter of 18 mm, and a height of 7 mm were prepared by press-molding the mixed powder so as to have a density of 6.5 g/cm 3 . The powder was pressed in a reducing atmosphere at 780X: sintering for 30 minutes, and the difference (standard deviation) of the sintered body density and the difference in the ring pressure strength (standard deviation) of the sintered body test piece were investigated. The results are shown in Table 2. As shown in Table 2, the difference in density of sintered bodies was large, and the difference in ring-pressure strength was also large, and the results were inferior in characteristics. Further, when copper powder coated with iron powder and graphite powder is not sintered and sintered under the same conditions as above, since the bronze powder 21 200838631 gold layer is not formed, the ring pressure tends to be somewhat lowered. , but the difference is the same result. Nine As shown above, in the comparative example, the apparent density of the powder characteristics was the lowest at 1.83 g/cm3, and the fluidity was at most 34.7 s/5 〇g, and the formability was poor. In addition, the difference in bulk density between the burned surnames is large, and the difference in ring-pressure strength is large, and the characteristics are poor. The same poor characteristics were also observed in the case where no tin powder or graphite powder was added. On the other hand, in the present embodiment, the apparent density of the powder characteristics was increased to 2.2 g/cm3 or more, and the fluidity was increased to 25 s/50 g or less. Further, the difference in the male and the degree of the sintered body is small, and the difference in the ring crushing strength is small, and the characteristics are good. In the case where no tin powder or graphite powder is added, the same good properties are obtained. As shown above, the composite powder for powder metallurgy of the present invention is coated with copper-coated iron powder or copper by using a steel content of 45 to 70% by weight, an apparent density of 2.2 g/cm3 or more, and a fluidity of 25 s/5 0 g or less. The powder of the iron powder and the electrolytic copper powder can be obtained by improving the density and fluidity of the powder, and the sintering characteristics such as increasing the ring pressure strength, and reducing the cost. It is suitable for copper-coated iron powder sintered oil-impregnated bearings. [Simple description of the diagram] (None) [Explanation of main component symbols] (None) 22