Abrasive wear properties of metal matrix composites produced by hot isostatic pressing/ Kuumisostaatpressimisel saadud maatriksmetallkomposiitide omadused abrasiivsel erosioonil

• Published in: Proceedings of the Estonian Academy of Sciences. Engineering Vol. 12; no. 4; p. 445
• Main Authors: Ala-Kleme, Sanna, Kivikyto-Reponen, Paivi, Liimatainen, Jari, Hellman, Jussi, Hannula, Simo-Pekka
• Format: Journal Article
• Language: English
• Published: Estonian Academy Publishers 01.12.2006
• ISSN: 1406-0175

Steel matrix composites are an attractive choice for paper, pulp and mineral crushing industries because of their wear resistant properties. In this paper the abrasive wear properties of the tool steel matrix composites are studied. The rubber wheel abrasion tests were carried out using six different composites. The tool steel Ralloy® WR6 was used as matrix material in all composites. Typically there is about 20 vol% VC in the matrix before the addition of the particle reinforcements. Reinforcements were either cemented carbides (WC-Co), cast tungsten carbides (WC) or niobium carbides (NbC). All the composites were so-called double dispersion composites having two distinctive reinforcement types. Although the wear resistance of the composite materials has been found to increase with reinforcement additions in rock crushing environment with multimode wear conditions, the pure abrasion resistance of the composites, having up to 30% additional reinforcements, was found inferior to the matrix tool steel. Based on the observations it is suggested that in order to improve the abrasive wear resistance of the tool steels by adding hard particles, the matrix--particle interface should be strong enough to prevent the detachment of particles and the amount of particles should be high enough to compensate the accelerated wear of the matrix because of hard particle wear debris. Key words: steel matrix composites, tool steel, cemented carbide, tungsten carbide, niobium carbide, abrasion, wear mechanisms. Tanu korgele kulumiskindlusele on terasmaatrikskomposiidid atraktiivsed materjalid paberi- ja tselluloositoostuses ning maakide peenestamisel. Artiklis on uuritud tooriistaterasmaatriksiga komposiitide omadusi abrasiivkulumise tingimustes. Katsed on labi viidud kuue erineva komposiidiga poorleva kummikettaga tekitatud abrasiooni korral. Maatriksmaterjalina on koikide komposiitide puhul kasutusel tooriistateras Ralloy® WR6. Tavaliselt on maatriksis enne sarrusosakeste lisamist ligikaudu 20 mahuprotsenti vanaadiumkarbiidi. Sarrusena on kasutusel kas kovasulam (WC-Co), valuvolframkarbiid (WC) voi nioobiumkarbiid (NbC). Koik materjalid on kaksikdispersioonkomposiidid, omades kahte erinevat sarruse liiki. Ehkki on leitud, et sarruselementide lisanditega komposiitmaterjalide kulumiskindlus suureneb kivipurustites mitmete kulumisliikide uhe aegsel toimel, on puhta abrasiooni kindlus juhul, kui sarruselementide osa uletab 30%, halvem kui maatrikstooriistaterasel. On kindlaks tehtud, et tooriistateraste kulumiskindluse tostmisel kovade osakeste lisamisega peab matriitsi ja osakeste vaheline side olema piisavalt tugev, et valtida osakeste eraldumist, ja osakeste kogus kullalt suur, et kompenseerida matriitsi suuremat kulumist kovade osakeste valjalangemise tottu.