Estudo do reaproveitamento de cavacos de uma liga bronze ao chumbo via rota de metalurgia do pó

Abstract

Due to environmental issues much discussed recently, alternative methods of chip reuse have been the subject of research, with the aim of reducing losses in metal processing routes and creating alternative ways of obtaining raw material for powder metallurgy and hot forming routes. In machining processes, a large amount of material is lost in the form of chips, which are mostly recycled by melting, but this process has material losses and a high operating cost. In view of this problem, this work proposes a study of the reuse of chips from a leaded copper alloy, resulting from a conventional machinning process. Apllying mechanical milling in a jar mill, particles were obtained in bands of micrometric sizes and for the purpose of microstructural analysis of the chip and the powder obtained both were submitted to X ray diffraction, whereas for morphological and chemical analysis of the powder the MEV / EDS technique was used. The samples were compacted by uniaxial pressing and sintered in controlled atmosphere furnace also in no controlled atmosphere. The Arquimedes test was applied on sintered material to determine the densification, and to obtain the mechanical properties a compression test was applied. The sinterization made on controlled atmosphere furnace was not efficient, the samples got green compact properties, hence there was not possible to proceed with the tests, the material submitted on no controlled atmosphere furnace get brittle e low strength, but there was possible do apply tests on it. The liquid phase was detected and it must be the cause of the inefficient sintering process.