Monitoring of Molten Pool Thermal History and its Significance in Laser Cladding Process

2017 ◽  
Author(s):  
Muvvala Gopinath ◽  
Debapriya Patra Karmakar ◽  
Ashish Kumar Nath
Keyword(s):  
Mechanical Properties ◽  
Laser Cladding ◽  
Thermal History ◽  
Molten Pool ◽  
Metal Matrix ◽  
Life Time ◽  
Wear Properties ◽  
Laves Phases ◽  
Slow Cooling ◽  
Calculated Effect

The current study focuses on the process monitoring of thermal history and its significance in laser cladding technology. Thermal history of the molten pool during laser cladding was monitored using an IR-pyrometer and the molten pool life time, solidification shelf duration and cooling rates were calculated. Effect of these on three different cases was studied in brief: (a) Elemental segregation in nickel based super alloy, (b) Wettability between metal matrix and WC particles and (c) Decomposition of TiC particles in metal matrix. It was found that with slow cooling rate, formation of Laves phases in Inconel 718 became dominant which is detrimental to the mechanical properties. Also, slow cooling resulted in the decomposition of TiC particles resulting in poor wear properties of the coating. In contrast to the above two cases where slow cooling was found to be detrimental for mechanical properties of the coating, it increased wettability as well as bonding through diffusion between the WC particles and the metal matrix. Also the effect of presence of TiC and WC in metal matrix on molten pool thermal history was studied. The microstructures, elemental segregations and fractured surfaces were characterized using SEM and EDS analyses.

Assessment of Microstructure and Mechanical Properties in Laser Cladding, Welding and Surface Polishing Through Online Monitoring of Thermal History

2019 ◽  
Author(s):  
Ashish Kumar Nath ◽  
Muvvala Gopinath
Keyword(s):  
Mechanical Properties ◽  
Laser Cladding ◽  
Thermal History ◽  
Thermal Stresses ◽  
Ceramic Coating ◽  
Online Monitoring ◽  
Laser Polishing ◽  
Melt Pool ◽  
On Line ◽  
Repeatability And Reproducibility

Abstract Monitoring and controlling the microstructure, phases, and thermal stresses in laser cladding of materials which determine their mechanical properties is essential for ensuring repeatability and reproducibility in refurbishing engineering parts and building functional parts by layer-by-layer deposition in additive manufacturing process. Several studies have been reported on on-line monitoring of temperature, melt-pool geometry, and porosity etc. in laser powder deposition process, but only a few on the assessment of solidification morphology, microstructure, and thermal stresses. Since these features are dictated by the melt-pool lifetime, cooling and solidification rates, their effects on the evolution of microstructure and the state of ceramic particles in laser deposition of Ni-super alloy and metal matrix composites of WC and TiC are investigated in the current study. Good correlation exists between the thermal history monitored online and the solidification characteristics. Process maps based on the melt-pool lifetime as a function of laser cladding parameters for these materials are developed. On-line monitoring of thermal cycle is extended to laser welding of stainless steel and titanium which are difficult to join together due to the formation of brittle intermetallic phases, and laser polishing of thermal sprayed ceramic coating to develop a better understanding and control of these processes. Melt-pool lifetime is found to have significant effect on the crack growth in fusion welding and by optimizing the former the later could be mitigated. Similarly, the cooling rate in laser polishing of thermal sprayed ceramic coating is found to have significant influence on the surface roughness and residual stress. These studies show that the online monitoring of thermal history can be exploited for controlling the process quality and ensuring the repeatability and reproducibility in different laser material processing modalities.

Investigation on Physical, Mechanical and Wear Properties of SiC Particulate Reinforced Aluminium Metal Matrix Composite

2015 ◽  
Vol 787 ◽  
pp. 588-592 ◽  
Author(s):  
Radhakrishnan Ganesh ◽  
J. Saranesh Kumar ◽  
R. Satya Prakash ◽  
K. Chandrasekaran
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Sintering Temperature ◽  
Reinforced Composites ◽  
Sliding Velocity ◽  
Wear Properties ◽  
Particulate Reinforced ◽  
Aluminium Metal

The paper presents the results of investigation on physical, mechanical and wear properties of SiC particulate reinforced aluminium metal matrix composite. The influence of reinforced ratios of 10, 15 and 20 wt. % of SiCp on mechanical properties and wear characters was examined. The effect of load and sliding velocity on wear behavior of composite was studied. It was observed that increase of weight fraction of reinforcement produced better physical and mechanical properties such as density and hardness with 37 µm SiC reinforced composite inspite of increased density the hardness drops above the critical sintering temperature of 550°C due to crazing of the matrix. With increased size of SiCp especially with higher temperature, density and hardness doesn’t supplement each other. Possible pooling/agglomeration in the case of medium and coarse sized reinforcement account for this. Wear decreases with increase in sintering temperature for 23 and 37 µm SiCp reinforced composites where as it increases for 67 µm SiCp reinforced composites. This could be attributed to formation of silanium compound contributing to discrete hardening of matrix. Wear tends to drop with sliding velocity being less contact between the pin and the disc but increases with normal load acting on the composite.

scholarly journals Aluminum Based Metal Matrix Composites Behavioral Studies with Different Reinforcements- A Review

2021 ◽  
Vol 9 (10) ◽  
pp. 1816-1822
Author(s):  
Paramjit Singh
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix ◽  
Density Ratio ◽  
High Strength ◽  
Stir Casting ◽  
Matrix Composites ◽  
Wear Properties ◽  
Mechanical And Tribological Properties ◽  
Behavioral Studies ◽  
Transportation Applications

Abstract: Aluminum alloy’s widely employed in transportation applications like: aerospace, aviation, marine and automobile sector due to their good mechanical properties, wear properties, corrosion behavior and high strength to density ratio. The current review article mainly highlights the effects of various reinforcements on mechanical and tribological properties of aluminum based metal matrix composite materials and focuses on the types of different reinforcements. Review revealed that, there is significant improvement in mechanical properties of AMMC’s with different reinforcements as compared to traditional base alloys. The reinforcements may be SiC, TiO2 , Al2O3 , fly ash, B4C, fiber, Zircon are incorporated in the stir casting or other methods. Keywords: AMMC, Reinforcements, Mechanical properties, Stir casting etc.

scholarly journals Mechanical and Wear Properties of Cold Extruded Al6063 Metal Matrix Alloy Reinforced with Silicon Carbide, Alumina and Cerium Oxide

2020 ◽  
Vol 9 (3) ◽  
pp. 4091-4097
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Weight Ratio ◽  
Extrusion Process ◽  
Cold Extrusion ◽  
Wear Properties ◽  
Composite Systems ◽  
Aesthetic Appearance

Metal matrix composite is considered in various engineering fields like Automobile, medical, electronics aerospace, marine, recreational sectors, of which Aluminum metal matrix composite is considered mostly because of its high strength to weight ratio, easy of fabrication, corrosion resistance, good aesthetic appearance and high resistance to wear etc. This paper concentrates on the effect of secondary processing (Cold Extrusion) on mechanical and wear properties of Al6063 reinforced with SiC, Al2O3 and CeO2 particles. Here composite systems prepared by varying reinforcement from 0% to 8% in steps of 2%. Stir casting route adopted for casting composite systems after casting the composite is made to pass through extrusion process with an extrusion ratio of 1.93 with a total strain of 1.45. All composite systems tested for mechanical properties as per ASTM and ISO standard. Wear test was conducted on pin on disc setup for different loads, reinforcement, sliding distance and sliding speed. Results reveals that due increase in reinforcement the mechanical properties have improved further improvement observed when subjected to extrusion process, similar observation was made for wear studies which conclude the wear rate is improved for extruded composite as compared to cast composite systems observed by various researchers.

Development of Aluminium MMC with Hybrid Reinforcement - A Review

2014 ◽  
Vol 808 ◽  
pp. 109-119 ◽  
Author(s):  
Swarndeep Singh ◽  
Rupinder Singh ◽  
Simranpreet Singh Gill
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix ◽  
High Strength ◽  
Wear Properties ◽  
Moulding Process ◽  
Production Route ◽  
Reinforcement Material ◽  
Promising Area ◽  
Hybrid Reinforcement ◽  
Aluminium Metal

Aluminium metal matrix composite (Al-MMC) is the most promising area for the researcher to develop a material of high strength, elastic modulus and wear resistance and low co-efficient of thermal expansion and weight. Un-hybrid and hybrid Al-MMC can be developmed by physical combination of aluminium with single and multiple reinforcement material, respectively. The improvement in mechanical properties has been achived with the reinforcement of Al2O3, SiC and combination of Al2O3, SiC (hybrid). Hybrid Al-MMCs are found superior to un-hybrid Al-MMCs in terms of wear properties. The fabrication of hybrid Al-MMC can be done with vacuum assisted moulding process (V process) in which no binder is used, which possesses many benefits over other sand casting processes. This production route will revolutionize the automobile and other industries.

scholarly journals Study of mechanical and wear characteristics of AL380 composite fabricated by introducing B4C using compo casting method

2018 ◽  
Vol 7 (4.5) ◽  
pp. 526
Author(s):  
Ch. V. M. Prasad ◽  
K. Mallikarjuna Rao
Keyword(s):  
Mechanical Properties ◽  
Wear Rate ◽  
Metal Matrix ◽  
Homogeneous Distribution ◽  
Al Alloy ◽  
Wear Properties ◽  
Casting Method ◽  
Pin On Disc ◽  
B4c Particles ◽  
Wear Tests

In the present work, Al380 Al alloy and B4C metal matrix composite was fabricated with different weight fractions (1%,2% and 3%) using compo-casting method. The wear properties of fabricated composite is tested by pin on disc apparatus. On different loads of 30N,60N and 90N the wear tests are performed. The mechanical properties of hardness and tensile strength are performed on brinell’s hardness apparatus and Ultimate tensile machine. The study of homogeneous distribution of B4C particles were examined by scanning electron microscope (SEM) in the composites. The result shows that the Al380 Al alloy reinforced with B4C particles, that composite improves the mechanical properties and wear rate. Increasing of wear rate with the increase in B4C particles in composites. Using Opti- cal microscope, the study of worn surfaces of pins were analyzed. 

Experimental investigation on stir casting of a metal matrix composite material

2021 ◽  
pp. 251659842110157
Author(s):  
Himanshu Kumar ◽  
S. Shiva
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Metal Matrix ◽  
Casting Process ◽  
Stir Casting ◽  
Holding Time ◽  
Reinforcement Particle ◽  
Processing Temperature ◽  
Wear Properties

In this article, Al7075 matrix with SiC as reinforcement particle was developed and the mechanical properties such as tensile strength, hardness, and impact strength was investigated. Aluminum is preferred as a matrix phase because Al alloys have low density and good ductility. Silicon carbide is chosen as a reinforcement phase due to its brittle and hard properties to enhance the wear properties. Mechanical properties of aluminum metal matrix have been tested at different temperatures and holding time. It shows an ultimate tensile strength of 121 N/mm2 at 800°C processing temperature and 20 mins of holding time. At a processing temperature of 850°C, it shows maximum hardness and impact strength. Among all the fabrication processes, stir casting is chosen because stir casting process is the simplest and cheapest for fabricating metal matrix composites (MMCs). Microelectronic and aerospace packaging industry requires a material with optimum hardness and impact strength to prevent the material from wear and impact during material handling. These MMCs will be a replacement for traditionally used materials such as W-Cu, BeO, and Kovar in packaging application.

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