Tratamento térmico em Zamac visando diminuir defeitos de porosidade
Heat treatment in Zamac to reduce porosity defects
Fernando Konarzewski Dienstmann, Luciane Taís Fuhr, Leonardo Felix Scheffel, Carlos Leonardo Pandolfo Carone, Fernando Dal Pont Morisso, Eduardo Luís Schneider, Sandra Raquel Kunst, Jane Zoppas Ferreira, Cláudia Trindade Oliveira
Resumo
O Zamac tem sido utilizado na indústria galvânica, principalmente, devido ao seu baixo ponto de fusão, o que permite a obtenção de peças com riqueza de detalhes, tais como peças do setor moveleiro, moda e metais sanitários. No entanto, os processos de sua obtenção, por injeção sob pressão e injeção centrífuga, geram porosidade e, consequentemente, aumento de sucata. Por outro lado, estudos mostraram que fusão por gravidade não apresenta tais problemas. Nesse sentido, o objetivo deste artigo foi tratar termicamente peças de Zamac injetadas sob pressão, com a finalidade de obter comportamento semelhante às peças fundidas por gravidade. Para tanto, peças injetadas sob pressão foram tratadas termicamente, abaixo da temperatura de fusão. A caracterização morfológica dessas amostras foi obtida por MEV. Observou-se que o tratamento térmico acima da temperatura eutetoide apresentou melhor resultado com respeito à porosidade observada.
Palavras-chave
Abstract
The Zamac has been used in the galvanic industry mainly due its low fusing point properties, which allows obtaining very detailed parts, like parts for furniture industry, fashion and health metals. However, its production processes, like pressure injection and centrifugal injection, generate an increase in porosity as well as waste. On the other hand, studies show that die casting leaked Zamac doesn’t show the same problems. In this sense, the goal for this work is to perform heat treatment in Zamac parts produced by pressure injection in order to obtain similar properties as the ones produced by die casting leakage. For this, the parts injected under pressure were thermally treated under their fusion temperature. It was observed that thermic treatment over the eutectoid temperature showed the best result, regarding the observed porosity.
Keywords
References
1 Wu Z, Sandlöbes S, Wu L, Hu W, Gottstein G, Korte-Kerzel S. Mechanical behaviour of Zn–Al–Cu–Mg alloys: Deformation mechanisms of as-cast microstructures. Materials Science and Engineering: A. 2016;651:675-687.
2 Wang F, Xiong B, Zhang Y, Liu H, Li Z, Li X, et al. Effect of Cu addition on microstructure and corrosion behavior of spray-deposited Zn–30Al alloy. Materials Science and Engineering: A. 2012;532:100-105.
3 Shin S, Lim K, Park I. Characteristics and microstructure of newly designed AleZn-based alloys for the die-casting process. Journal of Alloys and Compounds. 2016;671:517-526.
4 Marder AR. The metallurgy of zinc-coated steel. Progress in Materials Science. 2000;45(3):191-271.
5 Führ LT. Influência dos defeitos de solidificação na resistência à corrosão do Zamac. Novo Hamburgo: Universidade Feevale; 2012.
6 Marcolin P, Longhi M, Zini LP, Proença B, Malfatti CF, Battisti LC, et al. Influence of the pH and stirring speed of the electrodeposition bath in the performance of zinc and zinc-nanocomposite coatings. Materials Science Forum. 2017;899:283-288.
7 Ganivet M. Metalurgia das ligas de zinco: fundição. Belo. Horizonte: Serviço Nacional de Aprendizagem Industrial; 1987. (vol. 11).
8 Mojaver R, Shahverdi HR. Relationship between cooling rate, microstructure features and wear behavior in end-chill cast Zn-27% Al alloys containing more than 2% Cu. Wear. 2011;271(11-12):2899-2908.
9 Domínguez-Ríos C, Moreno MV, Torres-Sánchez R, Antúnez W, Aguilar-Elguézabal A, González-Hernández J. Effect of tartrate salt concentration on the morphological characteristics and composition of Cu-Zn electroless plating on zamak 5 zinc alloy. Surface and Coatings Technology. 2008;202(19):4848-4854.
10 Pinto H, Silva FJG. Optimisation of die casting process in Zamak alloys. Procedia Manufacturing. 2017;11:517-525.
11 Martinez Page MA, Weidenfeller B, Hartmann S. Influence of temperature and aging on the thermal diffusivity, thermal conductivity and heat capacity of a zinc die casting alloy. Journal of Alloys and Compounds. 2019;786(25):1060-1067.
12 American Society for Metals. Metals handbook. Metals Park: ASM. Metallography and microstructures. (vol. 9).
13 American Society for Metals. Metals handbook. Metals Park: ASM. Properties and selection: nonferrous alloys and special: purpose materials. (vol. 2).
14 Costa EM, Costa CE, Vecchia FD, Rick C, Scherer M, Santos CA, et al. Study of the influence of copper and magnesium additions on the microstructure formation of Zn–Al hypoeutectic alloys. Journal of Alloys and Compounds. 2009;488(1):89-99.
15 Rick CF. Estudo da liga à base de Zn-Al-Cu-Mg aplicada na fabricação de jóias folhadas. Porto Alegre: PUCRS; 2006.
16 Elvins J, Spittle JA, Worsley DA. Microstructural changes in zinc aluminium alloy galvanising as a function of processing parameters and their influence on corrosion. Corrosion Science. 2005;47(11):2740-2759.
17 Mapelli RF, Malfatti CF, Oliveira CT. Zinco: características e aplicações como elemento no desenvolvimento de tecnologia. Tecnologia e Tendências. 2014;9(1):1-12.
18 Marcolin P, Longhi M, Zini LP, Kunst SR, Zattera AJ, Fuhr LT, et al. Effects of the casting temperature in the leakage of Zamak 5. Materials Science Forum. 2017;899:458-462.
19 Callister WD. Ciência e engenharia de mateirias: uma introdução. 7. ed. Rio de Janeiro: LTC; 2008.
20 Schürz S, Luckeneder GH, Fleischanderl M, Mack P, Gsaller H, Kneissl AC, et al. Chemistry of corrosion products on Zn– Al–Mg alloy coated steel. Corrosion Science. 2010;52(10):3271-3279.
21 Kim S-J, Kim K-S, Kim S-S, Kang C-Y, Suganuma K. Characteristics of Zn-Al-Cu alloys for high temperature solder application. Materials Transactions. 2008;49(7):1531-1536.
22 Führ LT, Ludwig GA, Martins MR, Vecchia FD, Rieder EC, Malfatti C, et al. Effects of mould temperature in squeeze casting of Zamak 5. Materials Science Forum. 2014;775-776:729-732.
Submitted date:
04/08/2019
Accepted date:
06/23/2020
Facebook
Google+
Twitter
LinkedIn
Mendeley
StumbleUpon
CiteULike
Reddit
Email