THE POSSIBILITIES OF STRENGTHENING OF THE SURFACE LAYER OF NODULAR IRON BY LASER ALLOYING WITH SILICON NITRIDE ON THE EXAMPLE OF A ROCKER ARM

Tribologia ◽  
2017 ◽  
Vol 276 (6) ◽  
pp. 71-78
Author(s):  
Marta PACZKOWSKA
Keyword(s):  
Surface Layer ◽  
Silicon Nitride ◽  
Core Material ◽  
Beam Power ◽  
Laser Alloying ◽  
Dendritic Microstructure ◽  
Nodular Iron ◽  
Laser Beam Power ◽  
The One ◽  
Treatment Variant

In the order to increase the resistance to the friction wear of machine parts appropriate surface treatment application is needed. The aim of presented research was to evaluate the laser alloying with silicon nitride effects obtained in the surface layer of nodular iron and to select the laser treatment parameters that should be appropriate for the treatment of the one of the engine parts, which is a rocker arm. After implementation of silicon nitride into the nodular iron surface layer using laser heating, a uniform, fine, dendritic microstructure similar to the hardened white cast of the allayed zone was created in all performed variants. This microstructure resulted in at least 4-times higher hardness in comparison to the core material. The hardness and the alloyed zone dimensions were dependent on the laser heat treatment variant. The laser beam power density of 41 W/mm2 and its velocity of 2.8 mm/s were selected for the treatment of the rocker arm. It was caused by the effects obtained in the surface layer. With these parameters, it was possible to achieve the hardness of 1300 HV0.1 and the width of the alloying zone of over 4 mm, which is enough to strengthen the surface area of the rocker arm most exposed to the tribological wear.

Characterization Performance of Laser Melted Commercial Tool Steels

2010 ◽  
Vol 654-656 ◽  
pp. 1848-1851 ◽  
Author(s):  
Mirołsaw Bonek ◽  
Leszek Adam Dobrzański
Keyword(s):  
Surface Layer ◽  
Laser Beam ◽  
Molten Metal ◽  
Size Reduction ◽  
Beam Power ◽  
Laser Alloying ◽  
Dendritic Microstructure ◽  
Metal Base ◽  
Alloying Additions ◽  
Conventional Heat Treatment

The purpose of this research paper is focused on the X40CrMoV5-1 hot work tool steel surface layers improvement properties using high power diode laser. In the effect of laser alloying with powders of carbides occurs size reduction of microstructure, as well as dispersion hardening through fused in but partially dissolved carbides and consolidation through enrichment of surface layer in alloying additions coming from dissolving carbides. Introduced particles of carbides and in part remain undissolved, creating conglomerates being a result of fusion of undissolved powder grains into molten metal base. In effect of convection movements of material in the liquid state, conglomerates of carbides arrange themselves in the characteristic of swirl. Laser alloying of surface layer of investigated steel without introducing alloying additions into liquid molten metal pool, in the whole range of used laser power, causes size reduction of dendritic microstructure with the direction of crystallization consistent with the direction of heat carrying away from the zone of impact of laser beam. Remelting of the steel without introducing into liquid molten pool the alloying additions in the form of carbide powders, causes slight increase of properties of surface layer of investigated steel in comparison to its analogical properties obtained through conventional heat treatment, depending on the laser beam power implemented for remelting. The outcome of the research is an investigation showing the structural mechanisms accompanying laser alloying.

scholarly journals The Laser Alloying Process of Ductile Cast Iron Surface with Titanium

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 282
Author(s):  
Aleksandra Kotarska
Keyword(s):  
Cast Iron ◽  
Base Material ◽  
Ductile Cast Iron ◽  
Iron Surface ◽  
Beam Power ◽  
Rate Variation ◽  
Laser Alloying ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
Laser Beam Power

The article presents the results of the laser alloying process of ductile cast iron EN-GJS 350-22 surface with titanium. The laser alloying process was conducted on 2 kW high power diode laser (HPDDL) Rofin Sinar DL02 with rectangular focus and uniform power density distribution in the focus axis. The laser alloying was conducted with constant laser beam power and processing speed with titanium powder feed rate variation. The tests of the produced surface layers included macrostructure and microstructure observations, X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analysis, Vickers hardness, and solid particle erosion according to ASTM G76-04 standard. To assess the erosion mechanism, SEM observations of worn surfaces after erosive test were carried out. As a result of laser alloying of a ductile cast iron surface, the in situ metal-matrix composite structure was formed with TiC reinforcing particles. The microstructure change resulted in the increase of surface layers hardness and erosion resistance in comparison to the base material.

Structure of Titanium GRADE 1 after Laser Alloying with FeCr Powder

2020 ◽  
Vol 308 ◽  
pp. 157-170
Author(s):  
Maciej Wiśniowski ◽  
Tomasz Tański ◽  
Przemysław Snopiński
Keyword(s):  
Laser Beam ◽  
Nickel Powder ◽  
Beam Power ◽  
Laser Alloying ◽  
Surface Alloying ◽  
Laser Beam Power ◽  
Iron Nickel ◽  
Titanium Grade ◽  
Power Diode ◽  
High Power Diode Laser

Titanium alloys due to their low density and high mechanical properties are a group of materials that are being used willingly nowadays. A promising method of titanium heat treatment is laser surface alloying. Process parameters like laser beam power, its transverse speed, amount of alloying elements and shield gas, have influence on the material. Different chemical composition and morphology can be achieved resulting in a change of properties on the surface of the material. The paper presents the investigation of titanium GRADE 1 processed with iron‐nickel powder using laser alloying. The treatment was performed using a high power diode laser. Different laser beam power values were used.

The effect of laser treatment parameters on temperature distribution and thickness of laser-alloyed layers produced on Nimonic 80A-alloy

2017 ◽  
Vol 2 (83) ◽  
pp. 67-78 ◽  
Author(s):  
N. Makuch ◽  
P. Dziarski ◽  
M. Kulka
Keyword(s):  
Temperature Distribution ◽  
Laser Beam ◽  
Laser Treatment ◽  
High Hardness ◽  
Optical Microscope ◽  
Beam Power ◽  
Beam Diameter ◽  
Laser Alloying ◽  
Laser Beam Power ◽  
Nimonic 80A

Purpose: The aim of this paper was to determine the influence of laser treatment parameters on temperature distribution and thickness of laser-alloyed layers produced on Nimonic 80A-alloy. Design/methodology/approach: In this paper laser alloying was used in order to produce layers on Nimonic 80A-alloy surface. The three types of the alloying materials were applied: B, B+Nb and B+Mo. Microstructure observations were carried out using an optical microscope. The hardness measurements were performed using a Vickers method under a load of 0.981 N. For evaluation of temperature distribution the equations developed by Ashby and Esterling were used. Findings: The produced layers consisted of re-melted zone only and were characterized by high hardness (up to 1431 HV0.1). The increase in laser beam power caused an increase in thickness and decrease in hardness of re-melted zones. The temperature distribution was strongly dependent on laser treatment parameters and physical properties of alloying material. The higher laser beam power, used during laser alloying with boron, caused an increase in layer thickness and temperature on the treated surface. The addition of Mo or Nb for alloying paste caused changes in melting conditions. Research limitations/implications: The obtained results confirmed that laser beam power used for laser alloying influenced the thickness and hardness of the produced layers. Moreover, the role of type of alloying material and its thermal properties on melting condition was confirmed. Practical implications: Laser alloying is the promising method which can be used in order to form very thick and hard layers on the surface of Ni-base alloys. The obtained microstructure, thickness and properties strongly dependent on laser processing parameters such as laser beam diameter, laser beam power, scanning rate as well as on the type of alloying material and its thickness, or type of substrate material. Originality/value: In this paper the influence of alloying material on temperature distribution, thickness and hardness of the laser-alloyed layers was in details analyzed.

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