Wytwarzanie proszku kompozytu Cu-Fe-Al2O3

• Autorzy: Cyunczyk A.

Warianty tytułu

EN

Preparation of Cu-Fe-Al2O3 composite powder

• Języki publikacji: PL

Abstrakty

PL

Przedstawiono dwa warianty dwuetapowego sposobu wytwarzania proszku kompozytu Cu-Fe-Al2O3. W obu przypadkach pierwszy etap prowadził do uzyskania kompozytu Cu-AI2O3 w wyniku reakcji proszku aluminium z utlenionym powierzchniowo proszkiem miedzi. Drugi etap uzupełniającej obróbki, oparty na technice mechanicznego stopowania, był realizowany albo przez wielokrotne powtarzanie na przemian operacji prasowania proszku i zdzierania pilnikiem proszku z wyprasek, albo w wyniku obróbki proszków w młynie wibracyjnym. Porównano skuteczność uzyskanej w obu wariantach fazy dyspersyjnej pod względem stabilizacji drobnoziarnistej struktury metalu w wysokiej temperaturze.

EN

This work is a part of an effort to select the best composite powder and processing method for the production of a contact point of a spot welder. Cu-Fe-Al2O3 composite was the object of an experiment. Elemental powders of copper, iron and alu­minum were used as starting materials (Fig. 1). A two-stage manufacturing process was proposed and examined. The first step leads to Cu-Al2O3 composite. For this purpose a surface-oxidized electrolytic copper powder (weight loss in hydrogen 1.4%) and a flaky aluminum powder were pre-mixed and then cold pressed in the tool-steel die into cylindrical compacts 40 mm in diameter and 25 mm in height at the pressure of 200 MPa. Subsequent heat treatment in order to obtain the Cu-Al2O3 was carried out at 700°C in hydrogen for the period of 30 minutes. A lightly sintered material containing 3 vol.% Al2O3 was again powdering. The second step consists in mechanical alloying process in order to disperse ceramic particles in a metallic matrix and to add 1 mass % of Fe. Powders Cu-Al2O3 and Fe were pre-mixed by a mortar. Two techniques for mechanical alloying of mixture Cu-Al2O3-Fe were tested. A nontraditional variant of mechanical alloying utilizes repetition of powder pressing and compact filing. A schematic drawing of this procedure is shown in Fig. 2. Mixed powders were cold pressed into compacts 40 mm in diameter and 20 mm in height at the pressure of 400 MPa. Compacts were then powdered in a filing machine. Frequency of the reciprocating motion of a file was one stroke per second. The cycle pressing-filing was repeated fifteen times. A second variant of mechanical alloying was performed in a prototype vibration ball-mill. Scheme of this mill is shown in Fig. 3. Mechanical alloying was carried out using steel vial and balls, at a frequency of approximately of 50 Hz with the 3 mm amplitude. The material was milled for period of 6 hours. The MA-ed powders were cold pressed with a pressure of 400 MPa and then sintered at 1000°C in hydrogen for 3 hours. The powders and sintered samples have been then observed using scanning electron microscopy (Fig. 4) and optical microscopy (Fig. 5). It is shown that both the variants of mechanical alloying process under the given conditions provide for analogous fine-grain structures of the composite Cu-Fe-Al2O3, which are stable against the thermal influence. The repeated pressing-filing technique has appeared as an effective way of mechanical alloying.

Słowa kluczowe

PL

kompozyty; proszki kompozytowe

EN

composites; composite powders

• Wydawca: Wydawnictwo Politechniki Częstochowskiej
• Czasopismo: Kompozyty
• Rocznik: 2001
• Tom: R. 1, nr 2
• Strony: 151--154
• Opis fizyczny: Bibliogr. 4 poz., rys.

Twórcy

autor

Cyunczyk A.

• Politechniak Rzeszowska, Zakład Inżynierii Materiałowej, ul. Pola 2, 35-959 Rzeszów

Bibliografia

• [1] Cyunczyk A., Spiekane stopy Cu-Fe-Al2O3, Rudy i Metale Nieżelazne 1970, 15, 9, 462-467.
• [2] Cyunczyk A., Dyspersyjnie umocnione i utwardzalne stopy Cu-Fe-Al2O3, Rudy i Metale Nieżelazne 1970, 15, 10, 517-523.
• [3] Cyunczyk A., Ostrowski J., The Properties of Steel Powders Prepared by Atomization in Electric Arc, Powder Metall. Inter. 1976, 8, 1, 22-24.
• [4] Cyunczyk A., Rutkowski W., Żółkowski W., Sposób wytwarzania metali i stopów dyspersyjnie umocnionych, Patent PRL nr 65 379.