scholarly journals Strengthening Properties and Wear Resistance of the Cu-xNi-yCo-Cr-Si Alloy by Varying Ni/Co and Zr Addition

Lubricants ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 96
Author(s):  
Denis Ariel Avila-Salgado ◽  
Arturo Juárez-Hernández ◽  
José Cabral-Miramontes ◽  
José Luis Camacho-Martínez

This work examines the effect of nickel (Ni) and cobalt (Co) concentrations on wear resistance behavior of Cu-xNi-yCo-Cr-Si (x = 8−9 wt%, y = 1−2 wt%) and the zirconium (Zr) addition, in order to obtain an alloy with similar or better properties than the C17510 alloy. In this study, hardness and wear resistance mechanism behavior were associated with the microstructure evolution of these alloys with different aging strengthening conditions. Different heat treatments (HT) were applied to three alloys Cu-8Ni-2Co-1.6Cr-2Si wt% (L1), Cu-8.5Ni-1.5Co-1.6Cr-2Si wt% (L2) and Cu-9Ni-1Co-1.6Cr-2Si-0.18Fe-0.3Zr wt% (L3), the properties obtained were compared with C17510 alloy. Specimens were characterized by different metallographic techniques; the microstructural characterization was made with scanning electron microscopy (SEM) and revealed regions of dendritic morphologies. The solidification sequence is primary Cu dendrites and some phases in the interdendritic regions. The solution heat treatment decreased (ST) the Hardness Rockwell B (HRB) and wear rate resistance, and there was an increase with the first aging heat treatment (HT1) for each alloy. The most outstanding combination of properties was found for Cu-8.5Ni-1.5Co-1.6Cr-2Si wt% alloy (L2C3) with 100 ± 1 HRB and specific wear rate resistance of 1.2 × 10−4 mm3/Nm, after the first aging heat treatment.

2021 ◽  
Vol 1016 ◽  
pp. 137-144
Author(s):  
Pedro Akira Bazaglia Kuroda ◽  
Fernanda de Freitas Quadros ◽  
Mycaela Vieira Nascimento ◽  
Carlos Roberto Grandini

This paper deals with the study of the development, structural and microstructural characterization and, selected mechanical properties of Ti-25Ta-50Zr alloy for biomedical applications. The alloy was melted in an arc furnace and various solution heat treatments were performed to analyze the influence of the temperature and time on the structure, microstructure, microhardness and elastic modulus of the samples. The structural and microstructural results, obtained by X-ray diffraction and microscopy techniques, showed that the solution heat treatment performed at high temperatures induces the formation of the β phase, while solution heat treatment performed at low temperatures induces the formation of the α” and ω metastable phases. Regarding the effect of time, samples subjected to heat treatment for 6 hours have only the β phase, indicating that lengthy treatments suppress the α” phase. Regarding the hardness and elastic modulus, the alloy with the α” and ω phases, after treatment performed at a temperature of 500 °C, has a high hardness value and elastic modulus due to the presence of the ω phase that hardens and weakens alloys. The titanium alloys developed in this study have excellent mechanical properties results for use in the orthopedic area, better than many commercial materials such as cp-Ti, stainless steel and Co-Cr alloys.


2017 ◽  
Vol 890 ◽  
pp. 352-355
Author(s):  
Mohammed K. Gouda ◽  
Mohamed Abdel Hady Gepreel ◽  
Koichi Nakamura ◽  
Akihiko Chiba

The effect of Zr addition on the microstructure, cold workability and hardness of low-cost Ti-14Mn alloy was investigated. A set of alloys with1.5, 3 and6%wt. Zr were produced by arc melting. The alloys were subjected to solution heat treatment at 900 °C.Zr seems working as weak β-stabilizer in this Ti-14Mn-xZr alloy system. The effect of Zr-content on the cold workability was assessed.The cold workability of the Ti-14Mn-xZr alloys (withZr up to 6%) is higher than 90% reduction ration. The hardness slightly increased with the increase ofZr-content in Ti-14Mn-xZr alloys in both solution treated and cold rolled conditions.


2015 ◽  
Vol 68 (1) ◽  
pp. 91-96 ◽  
Author(s):  
José Wilmar Calderón Hernández ◽  
Duberney Hincapié Ladino ◽  
Cesar Roberto de Farias Azevedo ◽  
Neusa Alonso Falleiros

The effect of solution heat treatment on the pitting corrosion resistance of 17Cr-6Mn-5Ni-1.5Cu austenitic stainless steel in 0.6M NaCl aqueous solution was evaluated. UNS S30403 (304L) steel was used as benchmark material. Solution heat treatments (SHT) were conducted at 1010°C, 1040°C, 1070°C and 1100°C. The microstructural characterization revealed the presence of δ-ferrite, especially in the asreceived condition (AR). The SHT decreased the proportion of the ferrite phase. Mnrich precipitates were observed in the as-received condition of 17Cr-6Mn-5Ni-1.5Cu steel, but they were dissolved after the SHT, causing localized Mn enrichment in the austenite. Potentiodynamic tests showed that the pitting potential (Ep) in the 304L steel was not altered significantly after SHT. On the other hand, the value of Ep of the 17Cr-6Mn-5Ni-1.5Cu steel decreased after SHT. This detrimental effect was explained by the formation of Mn enrichment areas due to the solubilization of Mn-rich precipitates, which promoted preferential Cl- adsorption in these regions.


2015 ◽  
Vol 1110 ◽  
pp. 158-162
Author(s):  
Seung Pyo Hong ◽  
Chung Seok Kim

The effects of two-step solution heat treatment of aluminum alloy for lightweight automotive have been investigated. The test specimens, Al-6Si-2Cu alloys are prepared by gravity casting process. Solution heat treatments in this study are applied to improve of mechanical properties through a single-step or two-step solution heat treatment. For the microstructural characterization, inductively coupled plasma mass spectromerty (ICP-MS), optical microscope (OM) and scanning electron microscope (SEM) analyses are conducted in specimen. The X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analyses are also applied to identify the intermetallic phases with quantitative and qualitative analyses. Micro Vickers hardness and static tensile test are achieved. The microstructure of gravity casting specimen represents a typical dendrite structure having a secondary dendrite arm spacing (SDAS) of 37um. In addition to the Al matrix, a large amount of coarsen eutectic Si, Al2Cu intermetallic phases and Fe-rich phases are identified. After solution heat treatment, the mechanical properties of two-step solution heat treatment alloy show higher values than as-cast and single-step solution specimens. Consequentially, the two-step solution heat treatment could be used in automotive parts to improve mechanical properties.


Author(s):  
H Yousefpour Naghibi ◽  
H Omidvar ◽  
M Farahmand Nikoo

In this study, 6 mm thick AA6061-T6 plates were friction stir welded (FSWed) at different traveling speeds while Al2O3 nano-particles were incorporated between adjoining plates. The solution heat treatment was applied on samples for one hour at 540 ℃ and subsequently aged for 18 h at 180 ℃ to investigate the effect of post-weld heat treatment on mechanical properties of specimens. All joints were investigated macro- and micro-structurally. The microstructural characterization of the FSWed samples was carried out using scanning electron microscopy (SEM) and light microscopy techniques. Distribution of Al2O3 nano-particles in the stir zone was studied by SEM. The specimen FSWed at 40 mm/min exhibited the most homogeneous particles distribution. Tensile properties including ultimate tensile strength, elongation, and fracture surfaces were studied. Microhardness of specimens was also investigated. Surprisingly, all specimens exhibited inferior hardness compared to the as-received AA6061-T6 alloy. This phenomenon was attributed to the dissolution of precipitates during FSW process.


2006 ◽  
Vol 116-117 ◽  
pp. 181-184 ◽  
Author(s):  
Antonio Forn ◽  
Maite T. Baile ◽  
Enric Martín ◽  
Javier Goñi ◽  
I. Sarriés

The present work studies the effect the solution heat treatment, during artificial ageing and re-aging, has on the mechanical properties of an A357 aluminium alloy component formed by New Rheocasting. The effect that the evolution of silicon, during the solution treatment at various times, has on the mechanical properties was also examined. The mechanical properties were evaluated performing tensile tests, fractographical analysis and hardness tests. The microstructural characterization was made using optical and electronic microscopy.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2054 ◽  
Author(s):  
Tingting Wu ◽  
Jianxiu Su ◽  
Yongfeng Li ◽  
Hongyuan Zhao ◽  
Yaqi Zhang ◽  
...  

Excellent wear resistance of alumina ceramics is a desirable quality for many products. The purpose of this work was to improve the wear resistance of 99% alumina ceramics in an Al2O3–Gd2O3–SiO2–CaO–MgO (AGSCM) system. The content of Gd2O3 varied from 0.01% to 1%. A test of wear rate was performed in a ball milling apparatus in a water environment according to the Chinese industry standard. The compositions and microstructure of this material, as well as the effect of bulk density on wear rate, were studied. The effect of Gd2O3 on phases, grain growth mode, and grain boundary cohesion was investigated. It was found that Gd2O3 could refine grain size, form compressive stress of the grain boundary, and promote the crystallization of CaAl12O19. The wear rate of this material was as low as 0.00052‰ (the Chinese industry standard wear rate is ≤0.15‰). The mechanisms for wear resistance of AGSCM ceramics were also determined.


2019 ◽  
Vol 26 (10) ◽  
pp. 1950074
Author(s):  
ZHI-YUAN ZHU ◽  
JIA-HUAN CHEN ◽  
YUAN-FEI CAI ◽  
JIAN-QIANG LI

This study explored the friction and wear behavior of a Ni-based exhaust valve at high temperatures. Nickel-based superalloy was used with two types of processing states: the original forged sample and the sample under the standard T1 heat treatment. At room temperature and a loading force of 10[Formula: see text]N, the average friction coefficient of the T1 heat-treated specimen is 0.61, which was lower than that of the forged sample (0.78). The wear rate of this specimen was also lower than that of the forged sample at the same temperature and loading force. Thus, T1 heat treatment can significantly improve the wear resistance of the alloy because of [Formula: see text] phase and carbides. The wear rate was the minimum at 550∘C and increased again at 750∘C dominated by the formation and flake-off of the oxide film.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Krishna Mohan Singh ◽  
Akhilesh Kumar Chauhan

The aim of this research paper is to find the wear behaviour of Al7075 MMCs. In this investigation, the wear tests on the as-cast and age-hardened specimens were performed on an advanced rotary tribometer. The materials selected for the analysis are Al7075 as a matrix, and the reinforcements are boron carbide. By using stir casting, metal matrix composites are manufactured by adding B4C as a reinforcement particulate in Al7075. The fabricated composites were characterized and the wear behaviour of these composites was carried out on an advanced rotary tribometer. The wt. % of the reinforcements was taken as 6%, 8%, 10%, and 12%. The almost homogeneous blending of reinforcements is shown by the microstructural characterization of Al7075 MMCs. It is observed that due to the rise in weight percentage of the reinforcement to 12% higher hardness is obtained. For 12% of reinforcements, there is an increase in hardness due to the heat treatment than that of the as-cast composites. From this study, it was found that the wear rate is the function of the applied load, microstructure, and volume fraction of the reinforcements. The wear rate was increasing with the sliding velocity.


2017 ◽  
Vol 898 ◽  
pp. 413-421
Author(s):  
Wan Peng Yang ◽  
Jia Rong Li ◽  
Shi Zhong Liu ◽  
Jin Qian Zhao ◽  
Zhen Xue Shi ◽  
...  

The microstructures of low angle boundaries (LABs) of a third generation single crystal superalloy DD9 in as-cast state and after different heat treatment processes were studied by optical microscopy (OM) and field emission scanning electron microscopy (FESEM). The results showed that the as-cast LABs of DD9 alloy consisted of rod-like and bulk γ' phases with γ matrix between them, and there were eutectic γ-γ' precipitating at the LABs, as well as small amounts of discrete distribution of carbides. The γ' phase locateed at the grain boundaries was larger than that distributed on both sides of the grain boundaries. After the solution heat treatment, as-cast eutectic γ-γ' at LABs dissolved completely, and rod-like γ' phase was still found at some LABs. Meanwhile, the LABs were inclined to be straight compared to the as-cast state. The primary aging heat treatment made γ' phase at the LABs dissolved completely, and the secondary aging heat treatment resulted little change in the morphology of the LABs. Thus, the effect of the primary aging heat treatment on the microstructures of the LABs was greater than that of the secondary aging heat treatment.


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