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Particles morphology of aluminum bronze alloy submitted to mechanical milling (a) 30 h milling time with VC addition and (b) 60 h milling time with NbC addition.
Source publication
Aluminum bronze alloy is applied in environments that require materials of high mechanical resistance and wear, such as marine, oil & gas and aerospace ones. This study analyzes the densification of composites based on aluminum bronze with additions of the vanadium (VC) and niobium (NbC) carbides, and the influence of these carbides in the milling...
Contexts in source publication
Context 1
... characterizations of aluminum bronze resultant powders with addition of different carbides are shown is Fig. 1, where it is possible to observe a significant difference between particles in each case, with respect to sizes and shapes, due to presence of each carbide in ...
Context 2
... Fig. 1a shows the mixture of aluminum bronze powders with VC addition, milling for 30 h. It is observed that, in this condition, the powder presents very heterogeneous particles, with shapes varying from very small diameters to elongated particles with approximately 550 μm. The smaller particles have a rounded morphology and the larger ones ...
Context 3
... of aluminum bronze powders with VC addition, milling for 30 h. It is observed that, in this condition, the powder presents very heterogeneous particles, with shapes varying from very small diameters to elongated particles with approximately 550 μm. The smaller particles have a rounded morphology and the larger ones have an elongated morphology. Fig. 1b shows the aluminum bronze powder, milled for 60 h, with NbC addition. It is observed that, similar to the samples milled with VC, the powder has a very irregular granulometry, with particles varying from very small diameters to elongated particles with approximately 700 μm. However, aluminum bronze powder, milling with VC addition, has ...
Citations
... The process took place for 50 hours, with a stop at 15-minute intervals for each hour of work, with unidirectional rotations of 350 rpm through the planetary ball mill NQM 0.3L/Noah-Nuoya Corp, in an argon atmosphere to avoid oxidation. These parameters were chosen through DoE (Design of Experiments), published by DIAS, A. N. O. et al., 2019. The aluminum bronze bar samples were kindly provided by the company ELEB Equipamentos LTDA. ...
... It is known that the most effective way to improve the performance of materials manufactured using this technique is to increase its density, which can be achieved by using sintering method (9). It is possible to reach theoretical density of a reference material by 99% when optimal sintering parameters are used [11]. Eksi, compacted Al powder with 600 MPa pressure and applied sintering to the material at a temperature of 600 o C for 20 minutes, yielding a sample with a theoretical density of 99.3%. ...
... Although the microhardness value of the pure Al sample obtained from the compacting process was 67.8 HV, the most optimal microhardness value was calculated as 58 HV following a sintering process at 600oC for 45 minutes. It was thought that the reason for the occurrence of this situation is due to the process of removing the stresses on the powders by heat during sintering (11). ...
Addressing the need for light materials in today’s industry, the present study aims to analyze the effects of sintering parameters on pure Al material manufactured using powder metallurgy technique. 99% pure
and commercially obtained Al powder at a dimension of 180 µm was subjected to pre-heating and placed in a specially designed die. Al powder was compacted into a die using an upper punch with 500 MPa pressure and later removed from conical die for the sintering process. In order to find the optimal sintering temperature and duration, the compacted samples were sintered separately at 500oC, 550oC and 600oC for 45, 60 and 75 minutes.
for each temperature value. Microstructural analysis, microhardness test and density test of each sample obtained
from the sintering process were performed to determine the most optimal sintering durations at a given temperature, and changes caused during these processes were observed. As a result of examinations, it was determined that the optimal sintering temperature and time was 500 oC/60min, 550 oC/45min, 600 oC/45min. Finally, the samples obtained in different sintering durations for three different temperatures were subjected to a tensile test. According to the tensile test result s, it was determined that the most suitable sintering parameter for pure Al was 600 oC/45min
The present study aims to propose a new and non-complex sintering method in powder metallurgy in order to manufacture a light material with high mechanical properties. The proposed new sintering method is based on the principle that compaction is applied to a heated sample following classical sintering method. In this way, microstructure and mechanical properties of new samples manufactured using the proposed post sintering compaction method were compared with the samples manufactured using classical sintering method. In this context, in order to find the most optimal Al–Zn alloy ratio, different weight percentages of Zn (5–15–25–35–45%) were added to Al. When the manufactured alloys with classical sintering and post sintering compaction methods were compared, the most optimal alloy ratio was observed to be 15% Zn (Al–15Zn) manufactured using post sintering compaction method. In the next step, the matrix alloy with the most optimal ratio was reinforced with B4C in different weight percentages (1–2–3%) to manufacture Al matrix composites using post sintering compaction method. The microstructure analysis of the manufactured samples demonstrated that reinforcement particles were generally located at the grain boundaries and these particles caused the presence of porosities around them. In addition, mechanical test results indicated that increasing reinforcement ratio affected mechanical properties negatively. It can be thus concluded that a composite material with 1% B4C reinforcement ratio was superior to matrix alloy (Al–15Zn) in terms of microstructure, density, absorbed energy, hardness and compressive strength, and thus it is a critical reinforcement ratio in improving material properties.
In this paper, a new type of copper (Cu) matrix graphite composite was successfully prepared, which was reinforced with titanium nitride particles (TNPs) using powder metallurgy. These composites contained 2 wt % graphite as the lubricating phase and 1, 3, 5, 10, and 15 wt % TNPs as the reinforcing phase. The effects of different TNP contents on composite properties and the composites' wear mechanism were examined. The samples were characterized by microstructure, density, porosity, hardness, compressive yield strength, and friction wear testing. The results showed that, with TNP addition, the hardness, compressive strength, and friction and wear properties of the composites were improved. When the TNP content was >3 wt %, composite porosity gradually increased and the hardness, compressive strength, and friction and wear properties of the composites sharply decreased. With TNP addition, the main composite wear modes gradually changed from adhesive and abrasive wear to abrasive wear.
