Effects of Heat Treatment on Mechanical Properties of Ni-P-CNT Composite Coating

2015 ◽  
Vol 817 ◽  
pp. 493-497 ◽  
Author(s):  
Qin Shi ◽  
Wan Chang Sun ◽  
Jun Gao ◽  
Ying Wang ◽  
Miao Miao Tian

Ni-P-CNT nanocomposite coating was successfully co-deposited by electroless plating and the heat treatment was carried out at 200°C, 400°C, 600°C in nitrogen atmosphere respectively for a holding period of 1 h. The effects of heat treatment on the microstructure and mechanical properties of Ni-P-CNT composite coating were investigated. The results indicate that the heat treatment at 400°C can greatly improve the hardness and wear resistance of the composite coating. The reason is that Ni3P hard phase is greatly precipitated after the heat treatment, which played a strengthening effect. On the other hand, the precipitated Ni, Ni3P crystalline phases in the coating result in an increase of the amount of grain boundary. The increased amount of grain boundary broke the spread of shear force during friction process, and reduced the wear loss caused by friction pair. Compared with as-deposited coating, the coatings after heat treatment possess higher microhardness and wear resistance.

2014 ◽  
Vol 912-914 ◽  
pp. 200-203
Author(s):  
Yong Hong Liu ◽  
Jie Li ◽  
Wei Shao

The influence of heat-treatment on mechanical properties and wear resistance of ultra-high Mn steel was studied, micro-structure and fracture surface were analyzed by optical microscope (OM) and selected electron microscope (SEM). According to the results, optimized heat-treatment makes improvement in mechanical properties, and dispersed tiny carbides precipitate on Austenite matrix instead of grain boundary contributes to the excellent mechanical properties and wear resistance.


Author(s):  
YP Vaishnu ◽  
K Bindu Kumar ◽  
S Rani

The development of deposition of different metal processes established on electrodeposition of nickel, different alloy and composite coatings on different surfaces has attested an upsurge in interest among researchers. In latter years, these coatings have exhibited promising corrosion and wear resistance properties. Also, huge number of modern developments became most critical from macro to nano level applications. It is well known that one may shape the microstructure and the phase present in the material to recover the mechanical properties of highly pure materials, specifically metals. Co-deposition of fine particles inside a metal matrix to generate composite coatings has treated as a practical strategy to acquire enhanced mechanical properties like wear resistance, corrosion resistance and lubrication. In this work, CuO/Ni composite coatings are processed on the small cylindrical pin by electro brush plating to evaluate the wear and corrosion resistance. To examine the effects about the different parameters of processes on wear loss of CuO/Ni composite coating, L16(44) orthogonal experiment is designed and conducted with four process parameters (voltage, concentration of nanoCuO particles in g/l, temperature and thickness) which are selected as factors. Design of experiment is employed to resolve the effects of process parameters on the wear loss of composite coatings. It is concluded that concentration of CuO nanoparticle and voltage are the most significant factors for the wear loss.


Author(s):  
Sagar Sarkar ◽  
Cheruvu Siva Kumar ◽  
Ashish Kumar Nath

One of the most popular additive manufacturing processes is laser based direct metal laser sintering process which enables us to make complex three dimensional parts directly from CAD models. Due to layer by layer formation, parts built in this process tend to be anisotropic in nature. Suitable heat treatment can reduce this anisotropic behaviour by changing the microstructure. Depending upon the applications, a wide range of mechanical properties can be achieved between 482–621° C temperature for precipitation-hardened stainless steels. In the present study effect of different heat treatment processes, namely solution annealing, ageing and overaging, on tensile strength, hardness and wear properties has been studied in detail. Suitable metallurgical and mechanical characterization techniques have been applied wherever required, to support the experimental observations. Results show H900 condition gives highest yield strength and lowest tensile strain at break whereas solution annealing gives lowest yield strength and as-built condition gives highest tensile strain at break. SEM images show that H900 and H1150 condition produces brittle and ductile morphology respectively which in turn gives highest and lowest hardness value respectively.XRD analysis shows presence of austenite phases which can increase hardness at the cost of ductility. Average wear loss for H900 condition is highest whereas it is lowest for solution annealed condition. Further optical and SEM images have been taken to understand the basic wear mechanism involved.


2011 ◽  
Vol 214 ◽  
pp. 108-112 ◽  
Author(s):  
Prachya Peasura ◽  
Bovornchok Poopat

The Inconel X-750 indicates good hot corrosion resistance, high stability and strength at high temperatures and for this reason the alloy is used in manufacturing of gas turbine hot components. The objective of this research was study the effect of post weld heat treatment (PWHT) on fusion zone and heat affected zone microstructure and mechanical properties of Inconel X-750 weld. After welding, samples were solutionized at 1500 0C. Various aging temperature and times were studied. The results show that aging temperature and time during PWHT can greatly affect microstructure and hardness in fusion zone and heat affected zone. As high aging temperature was used, the grain size also increased and M23C6 at the grain boundary decreased. This can result in decreased of hardness. Moreover excessive aging temperature can result in increasing MC carbide intensity in parent phase (austenite). It can also be observed that M23C6 at the grain boundary decreased due to high aging temperature. This resulted in decreasing of hardness of weld metal and heat affected zone. Experimental results showed that the aging temperature 705 0C aging time of 24 hours provided smaller grain size, suitable size and intensity of MC carbide resulting in higher hardness both in weld metal and HAZ.


2018 ◽  
Vol 12 (4) ◽  
pp. 4180-4190
Author(s):  
Ananda Hegde ◽  
Sathyashankara Sharma ◽  
Gowri Shankar M. C

When the ductile iron which is also known as Spheroidal Graphite (SG) iron, is subjected to austempering heat treatment, the material is known as austempered ductile iron (ADI). This material has good mechanical properties and has various applications in different fields. This revolutionary material with its excellent combination of strength, ductility, toughness and wear resistance has the potential to replace some of the commonly used conventional materials such as steel, aluminium and other light weight alloys as it offers production advantage as well. One of the problems encountered during manufacturing is machining of ADI parts owing to its high hardness and wear resistance. Many researchers over a period of time have reported the machinability aspects of the ADI. This paper presents a review on the developments made on the machinability aspects of ADI along with other mechanical properties.


Author(s):  
T.A. Krylova ◽  
◽  
Y.A. Chumakov ◽  

The effect of heat treatment on the structure and properties of composite coatings based on chromium carbide with titanium carbide fabricated by non-vacuum electron beam cladding without has been studied. It was shown that tempering leads to a decrease in microhardness and wear resistance, which is associated with the decomposition of the austenitic structure with the formation of a soft ferrite-carbide structure. The post heat treatment tempering was showed to decrease of microhardness and wear resistance, which leads to the decomposition of the austenitic structure with the formation of a soft ferrite-carbide structure. The bulk quenching of coatings after tempering leads to an increase in microhardness comparable to the values of microhardness in the initial state after electron beam cladding, due to the formation of high hard martensite. The wear resistance of composite coatings after tempering is lower than after cladding due to brittle martensite, which is not able to hold solid carbide particles. The composite coatings obtained at the optimal processing conditions have a combination of improved properties and do not require additional heat treatment, resulting in structural changes, causing a decrease in mechanical properties.


2018 ◽  
Vol 27 (47) ◽  
pp. 101
Author(s):  
Sandra Arias ◽  
Maryory Gómez ◽  
Esteban Correa ◽  
Félix Echeverría-Echeverría ◽  
Juan Guillermo Castaño

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.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4223 ◽  
Author(s):  
Xi Zhao ◽  
Shuchang Li ◽  
Fafa Yan ◽  
Zhimin Zhang ◽  
Yaojin Wu

Microstructure evolution and mechanical properties of AZ80 Mg alloy during annular channel angular extrusion (350 °C) and heat treatment with varying parameters were investigated, respectively. The results showed that dynamic recrystallization of Mg grains was developed and the dendritic eutectic β-Mg17Al12 phases formed during the solidification were broken into small β-phase particles after hot extrusion. Moreover, a weak texture with two dominant peaks formed owing to the significant grain refinement and the enhanced activation of pyramidal <c + a> slip at relative high temperature. The tension tests showed that both the yield strength and ultimate tensile strength of the extruded alloy were dramatically improved owing to the joint strengthening effect of fine grain and β-phase particles as compared with the homogenized sample. The solution treatment achieved the good plasticity of the alloy resulting from the dissolution of β-phases and the development of more equiaxed grains, while the direct-aging process led to poor alloy elongation as a result of residual eutectic β-phases. After solution and aging treatment, simultaneous bonding strength and plasticity of the alloy were achieved, as a consequence of dissolution of coarse eutectic β-phases and heterogeneous precipitation of a large quantity of newly formed β-phases with both the morphologies of continuous and discontinuous precipitates.


1977 ◽  
Vol 47 (2) ◽  
pp. 132-139 ◽  
Author(s):  
T. K. Bhattacharya ◽  
MD. Abubakkar ◽  
A. K. Mukherjee

The changes in the size distribution of polycaprolactam that take place during melting and melt-spinning have been studied. During melting under a nitrogen atmosphere, thermal degradation as well as post polymerization takes place. Spinning the polymer under atmospheric conditions, thermal, thermo-oxidative, and mechanical degradations come into play. Post polymerization is also operative in this case. The net change that is being encountered in these processes is a broader size distribution of the polymer as compared to that of the parent one. The effects of three different anti-oxidants, which are paraphenylene diamine derivatives, on the size distribution of polycaprolactam during melting and melt-spinning have been studied. Anti-oxidants are found to check the broadening of the size-distribution curve and retain the mechanical properties of the material to an appreciable extent, even after heat treatment at a temperature of 160°C for 8 hours under atmospheric condition.


Sign in / Sign up

Export Citation Format

Share Document