Effects of Molybdenum Content and Heat Treatment on Mechanical and Tribological Properties of a Low-Carbon Stellite® Alloy

2006 ◽  
Vol 129 (4) ◽  
pp. 523-529 ◽  
Author(s):  
Ping Huang ◽  
Rong Liu ◽  
Xijia Wu ◽  
Matthew X. Yao
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Tribological Properties ◽  
Standard Test ◽  
Test Method ◽  
Low Carbon ◽  
Casting Technique ◽  
Mechanical And Tribological Properties ◽  
Tension Testing ◽  
Mo Content

The chemical composition of Stellite® 21 alloy was modified by doubling the molybdenum (Mo) content for enhanced corrosion and wear resistance. The specimens were fabricated using a casting technique. Half of the specimens experienced a heat treatment at 1050°C for an hour. The microstructure and phase analyses of the specimens were conducted using electron scanning microscopy and X-ray diffraction. The mechanical properties of the specimens were determined in terms of the ASTM Standard Test Method for Tension Testing of Metallic Materials (E8-96). The mechanical behaviors of individual phases in the specimen materials were investigated using a nano-indentation technique. The wear resistance of the specimens was evaluated on a ball-on-disk tribometer. The experimental results revealed that the increased Mo content had significant effects on the mechanical and tribological properties of the low-carbon Stellite® alloy and the heat treatment also influenced these properties.

Influence of thermal cycling modes on VK8 hard alloy mechanical and tribological properties

2020 ◽  
pp. 55-65
Author(s):  
S. I. Bogodukhov ◽  
E. S. Kozik ◽  
E. V. Svidenko
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Wear Resistance ◽  
Thermal Cycling ◽  
Hard Alloy ◽  
Tribological Properties ◽  
High Speed ◽  
Metal Cutting ◽  
Hard Alloys ◽  
Mechanical And Tribological Properties

Hard alloys are popular materials widely used in the toolmaking industry. Refractory carbides included in their composition make carbide tools very hard (80 to 92 HRA) and heat-resistant (800 to 1000 °С) so as they can be used at cutting speeds several times higher than those used for high-speed steels. However, hard alloys differ from the latter by lower strength (1000 to 1500 MPa) and the absence of impact strength, and this constitutes an urgent problem. We studied the influence of thermal cycling modes on the mechanical and tribological properties of VK8 (WC–8Co) hard alloy used in the manufacture of cutters and cutting inserts for metal working on metal-cutting machines. As the object of study, we selected 5×5×35 mm billets made of VK8 (WC–8Co) alloy manufactured by powder metallurgy methods at Dimitrovgrad Tool Plant. The following criteria were selected for heat treatment mode evaluation: Vickers hardness, flexural strength, and mass wear resistance (as compared to the wear of asreceived samples that were not heat treated). Plates in the initial state and after heat treatment were subjected to abrasion tests. Wear results were evaluated by the change in the mass of plates. Regularities of the influence of various time and temperature conditions of heat treatment on the tribological properties of products made of VK group tungsten hard alloys were determined. An increase in the number of thermal cycling cycles improved such mechanical properties of the VK8 hard alloy as strength and hardness. When repeating the cycles five times, an increase in abrasive wear resistance was obtained compared to the initial nonheat-treated sample. The elemental composition of the VK8 hard alloy changed insignificantly after thermal cycling, only a slight increase in oxygen was observed on the surface of plates. The grain size after thermal cycling increased in comparison with the initial VK8 hard alloy. It was found that VK8 hard alloy thermocyclic treatment leads to a change in the phase composition. X-ray phase analysis showed the presence of a large amount of α-Co with an hcp-type lattice on the surface of a hard alloy and a solid solution of WC in α-Co. A change in the cobalt modification ratio causes a decrease in microstresses. An analysis of the carbide phase structure state showed that the size of crystallites and microstresses changed after thermal cycling. The lattice constant of the cobalt cubic solid solution decreased, which may indicate a decrease in the amount of tungsten carbide and carbon dissolved in it. Statistical processing of experimental results included the calculation of the average value of the mechanical property, its dispersion and standard deviation in the selected confidence interval.

scholarly journals Effects of Nitride on the Tribological Properties of the Low Carbon Alloy Steel

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yuh-Ping Chang ◽  
Jin-Chi Wang ◽  
Jeng-Haur Horng ◽  
Li-Ming Chu ◽  
Yih-Chyun Hwang
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Alloy Steel ◽  
Tribological Properties ◽  
Wear Particles ◽  
Low Carbon ◽  
Low Friction ◽  
Treatment Technology ◽  
Surface Magnetization ◽  
Composite Heat

The technology of composite heat treatment is used popularly for low friction and wear resistance of drive elements. A large number of papers about the heat treatment technology had been proposed. Especially, the nitride treatment has been used widely for the purpose of wear resistance and low friction in the industry. Therefore, the self-developed vertical ball/disk friction tester with the measurement system was used to study the effects of nitride on the tribological properties of the low carbon alloy steel—SCM415— in this study. The experiments were conducted under dry and severe wear conditions. The variations of friction coefficient and surface magnetization were simultaneously recorded during dynamic friction process. After each test, the microstructures of the wear particles were observed and analyzed under a SEM, and the depth of wear track is measured by means of a surface tester. According to the experimental results, the wear resistance of the specimens with carburizing-nitride is significantly larger than the case of nitride-carburizing. Moreover, the surface magnetization was especially larger for the case of nitride-carburizing. As a result, the wear particles always stay in the interfaces and the wear mechanism becomes complex. Therefore, it is necessary to put nitride after carburizing for the composite heat treatments.

Fabrication and Characterization of Al-0.4%Si-0.5%Mg - SiCp Using Permanent Mould Casting Technique

2017 ◽  
Vol 867 ◽  
pp. 34-40 ◽  
Author(s):  
Adithya Parthasarathy ◽  
L. Avinash ◽  
K.N. Varun Kumar ◽  
Basavaraj Sajjan ◽  
S. Varun
Keyword(s):  
Heat Treatment ◽  
Tribological Properties ◽  
Solution Treatment ◽  
Weight Fraction ◽  
Constant Load ◽  
Artificial Ageing ◽  
Casting Technique ◽  
Mechanical And Tribological Properties ◽  
Pin On Disc ◽  
Mould Casting

Production of A6063/SiC composite with various weight fractions (3%, 6%, 9%) were prepared by using permanent mould casting was investigated. The preferred mean particle size of SiC is 60 μm. In addition, A6063 alloys were cast for comparison purposes. The alloys and composites were given a T6 heat treatment process (solution treatment at 520 °C, water quenching at room temperature and artificial ageing at 180 °C), Also Microstructure, hardness and tensile properties of these composites were evaluated and compared. In addition, tribological properties of these composites were evaluated using a Pin-on-Disc apparatus with various parameters (constant load of 10N and varying velocities as follows 0.5m/s, 1m/s, 1.5m/s, 2m/s) .The microstructure of the composites shows homogenous distribution of SiC particles in the Al matrix except in the A6063/9% SiC composite. The wear and mechanical properties of composites improve with increasing the weight fraction of SiC Wear morphology studies show that higher wear rate in case of unreinforced specimen compared to heat treated composites. Whereas with the increase in SiC content, the material tends to fail in brittle mode. The aim of present study is to evaluate the effect of heat treatment on the mechanical and tribological properties of aluminum alloy A6063 /SiC metal matrix composite.

scholarly journals The Effect of Polytetrafluoroethylene (PTFE) Particles on Microstructural and Tribological Properties of Electroless Ni-P+PTFE Duplex Coatings Developed for Geothermal Applications

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 670
Author(s):  
Gifty Oppong Boakye ◽  
Arna María Ormsdóttir ◽  
Baldur Geir Gunnarsson ◽  
Sandeep Irukuvarghula ◽  
Raja Khan ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Complex Geometry ◽  
Corrosion And Wear ◽  
Functional Layer ◽  
Scaling Properties ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Duplex Coating ◽  
Wear Protection

The selection of electroless nickel-phosphorus plating (ENP) has been inclined towards their properties and advantages with complex geometry applications. These properties include coating uniformity, low surface roughness, low wettability, high hardness, lubricity, and corrosion- and wear-resistance. Materials used in geothermal environments are exposed to harsh conditions such as high loads, temperature, and corrosive fluids, causing corrosion, scaling, erosion and wear of components. To improve the corrosion- and wear-resistance and anti-scaling properties of materials for geothermal environment, a ENP duplex coating with PTFE nanoparticles was developed and deposited on mild steel within the H2020 EU Geo-Coat project. ENP thin adhesive layer and ENP+PTFE top functional layer form the duplex structure of the coating. The objective of this study was to test the mechanical and tribological properties of the developed ENP-PTFE coatings with varying PTFE content. The microstructural, mechanical and tribological properties of the as-deposited coating with increasing PTFE content in the top functional layer in the order: ENP1, ENP2 and ENP3 were evaluated. The results showed maximum wear protection of the substrates at the lowest load; however, increasing load and sliding cycles increased the wear rates, and 79% increased lubrication was recorded for the ENP2 duplex coating. The wear performance of ENP3 greatly improved with a wear resistance of 8.3 × 104 m/mm3 compared to 6.9 × 104 m/mm3 for ENP2 and 2.1 × 104 m/mm3 for ENP1. The results are applicable in developing low friction, hydrophobic or wear-resistive surfaces for geothermal application.

scholarly journals Effect of heat treatment on the tribological properties of Nickel-Boron electroless coating

2018 ◽  
Vol 27 (47) ◽  
pp. 101
Author(s):  
Sandra Arias ◽  
Maryory Gómez ◽  
Esteban Correa ◽  
Félix Echeverría-Echeverría ◽  
Juan Guillermo Castaño
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Resistance ◽  
Carbon Steel ◽  
Tribological Properties ◽  
Tribological Performance ◽  
Dry Sliding ◽  
Electroless Coating ◽  
Before And After ◽  
Properties Of Materials

Nickel-Boron autocatalytic coatings are widely used in several industries to improve mechanical properties of materials such as hardness and wear resistance. Tribological properties were evaluated in Ni-B autocatalytic coatings deposited on AISI/SAE 1018 carbon steel before and after a heat treatment at 450 °C for one hour. Tribological tests were carried out by dry sliding, using a load of 5 N and a sliding speed of 0.012 m/s, in a homemade ball-on-disk tribometer, which followed ASTM G99 standard. According to the tribological evaluation, the heat treatments applied to Ni-B coatings improved their tribological performance. This research corroborates that by applying an adequate heat treatment, hardness and wear resistance of Ni-B coatings can be improved significantly.

scholarly journals Mechanical and tribological properties of B-C-N coatings sliding against different wood balls

2019 ◽  
Vol 26 (1) ◽  
pp. 402-411 ◽  
Author(s):  
Zhiwei Wu ◽  
Yan Wang ◽  
Sihao Li ◽  
Xiaoyong Wang ◽  
Zhaojun Xu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
316L Stainless Steel ◽  
Rf Magnetron Sputtering ◽  
Chemical Compositions ◽  
Low Friction ◽  
Friction Behavior ◽  
Mechanical And Tribological Properties ◽  
Bonding Structure ◽  
C And N

AbstractBCN coatings with different chemical compositions were prepared using RF magnetron sputtering via adjusting N2 flow. The influence of N2 flow on the bonding structure, mechanical and tribological properties of coating was studied. The structural analysis indicated the coexistence of B-N, B-C, and N-C bonds, suggesting the formation of a ternary BCN hybridization. The maximum Vickers hardness of 1614.7 HV was obtained at the low N2 flow (5 sccm), whereas the adhesion strength of BCN coatings on 316L stainless steel was improved with an increase of N2 flow. The friction behavior of BCN coatings sliding against different materials (acerbic, beech and lauan wood) was performed using ball-on-disk tribo-meter in air. The low friction coefficient was easier to obtain as sliding against hardwood i.e. acerbic balls. BCN-5 and BCN-10 coatings presented better wear resistance regardless of softwood or hardwood, whilst other two coatings were more suitable for mating softwood i.e. beech and lauan.

scholarly journals The effect of heat treatment on the mechanical and tribological properties of dual size SiC reinforced A357 matrix composites

2020 ◽  
Vol 9 (3) ◽  
pp. 6434-6452
Author(s):  
Avinash Lakshmikanthan ◽  
Ram Prabhu T. ◽  
Sai Babu Udayagiri ◽  
Praveennath G. Koppad ◽  
Manoj Gupta ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Tribological Properties ◽  
Matrix Composites ◽  
Mechanical And Tribological Properties
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