Showing 4 results for Laser Cladding
P. Shayanfar, H. Daneshmanesh, K. Janghorban,
Volume 6, Issue 1 (8-2020)
Abstract
In this study, the effect of overlapping percentage on microstructure and mechanical properties of a single-pass coating by Inconel 625 powder laser has been investigated for quench-tempered ASTM A592 steel. In order to have a structural analysis, the inter dendritic distance was evaluated. For this purpose, scanning electron microscopy (FESEM) and Digimizer software were adopted. In order to investigate mechanical properties, elastic modulus, toughness, and micro hardness were evaluated. For the evaluation of elastic modulus, Noop indentation method was used, and for toughness studies, Evans method was applied. After the investigation, it was found that in the overlapping of single-pass 50% coatings, the heat input value is lower than overlapping in single-pass 75% coatings. It also contains a finer structure with much higher mechanical properties. This is in such a way that the inter dendritic distance in single-pass 50% coatings is about 0.91 µm. The average diameter of the dendritic columns is about 0.32 µm, hardness value is about 10%, Knoop hardness is about 9 units, elastic modulus is about 37 GPa, and toughness is about 9 MPa m1/2 higher in comparison with the 75% overlapping case.
M.h. Zakeri, A.r. Nasresfahani, S.m. Barekat,
Volume 7, Issue 2 (1-2022)
Abstract
In this research, the microstructure of Inconel 625 cladded layer on ASTM A575 steel has been investigated. By examining different parameters, the optimal single-pass sample with the least amount of dilution, porosity and fusion and suitable wetting angle was determined. Then cladding process with the optimal parameter was performed. The microstructure of the cladding layer was evaluated from the base metal to the top. Due to different cooling rates, dendritic morphologies were observed at different distances. Also, the cladding layer was free of any cavities, porosity and cracks and its thickness was 0.9 mm (900 micrometers). The results of (XRD) and (EDS) analyzes indicate thatthe γphase is formed and there is a relatively uniform distribution of elements in the cladding layer. These results also indicate that no change in the chemical composition of the substrate surface was achieved near the interface.The hardness test results also show that the hardness starts from 450 VHN at the top surface and reaches to 135 VHN in the base metal with a gentle slope. This slope of hardness can be attributed to the cooling or heating rates of the substrate.
M.r. Borhani, S.r. Shoja Razavi, F. Kermani, M. Erfan Manesh, S.m. Barekat, H. Naderi Samani, M. Shahsavari,
Volume 8, Issue 2 (1-2023)
Abstract
The purpose of this research is to laser cladding of stellite6 and stainless steel 17-4PH powders on the substrate of stainless steel 17-4PH, and investigate its solidification microstructure. The results showed that the microstructure of the stellite6 cladding has a cobalt solid solution ground phase with an FCC structure and Cr7C3 and Cr23C6 carbides. Also, the values of the primary dendrite distance and the distance of the secondary dendrite arm have decreased by moving away from the interface; The reason for this is related to the difference in the cooling rate in different parts of the coating. The microstructure of 17-4PH stainless steel coating includes martensitic, ferritic, and austenitic phases; Due to the same chemical composition of the substrate and the cladding, the weight percentage of elements such as iron, nickel, chromium, and copper did not change from the cladding to the interface. It indicates the uniformity of the chemical composition of the cladding and the substrate. The calculated microhardness for the cladding of stellite6, the substrate and the cladding of stainless steel 7-4PH is about 480, 350, and 350 respectively. The reason for the higher microhardness of the cladding is the presence of chromium carbides (Cr7C3 and Cr23C6) formed in the cobalt field and the cobalt solid solution field of the cladding.
B. Agharazi, S. R. Shoja Razavi, S. M. Barekat, M. R. Borhani, M. Erfanmanesh,
Volume 11, Issue 1 (7-2025)
Abstract
This experimental-statistical study investigates the influence of laser cladding parameters—laser power (700–900 W), scanning speed (6–8 mm/s), and wire feed rate (70–80 mm/min)—on the geometric characteristics of single-pass coatings of 2507 duplex stainless steel on a VCN200 substrate. Experimental data were analyzed using Response Surface Methodology (RSM) with a three-factor, four-level design matrix. Measurements including clad width (W), height (H), penetration depth (b), wettability angle (Z), and dilution percentage (D) were obtained via ImageJ software. Results indicated that increasing laser power from 700 to 900 W led to a 14% increase in clad width (from 1417 to 1744 µm), a 33% rise in clad height (from 450 to 594 µm), a 6% increase in penetration depth (from 88 to 93 µm), and a 3% improvement in wettability angle (from 71° to 69°). In contrast, increasing scanning speed from 6 to 8 mm/s reduced clad width by 12% (from 1513 to 1787 µm), clad height by 31% (from 650 to 573 µm), and wettability angle by 15% (from 67° to 78°), while enhancing penetration depth by 4% (from 85 to 84 µm) and dilution by 19% (from 58% to 53%). Moreover, raising the wire feed rate from 70 to 80 mm/min increased clad height by 13% (from 502 to 747 µm) and wettability angle by 4% (from 75° to 78°), but decreased dilution by 19% (from 59% to 48%).