Novel Powder Modification Method for the Cold Spray of Hard Steels

2021 ◽  
Author(s):  
D. Poirier ◽  
Y. Thomas ◽  
B. Guerreiro ◽  
M. Martin ◽  
M. Aghasibeig ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cold Spray ◽  
Steel Powder ◽  
Deposition Efficiency ◽  
Maximum Temperature ◽  
Powder Size ◽  
H13 Tool Steel ◽  
Treatment Conditions ◽  
Dense Deposits ◽  
Modification Method

Abstract A novel powder modification method based on the simultaneous softening and agglomeration of steel powders via heat treatment in a rotary tube furnace has been investigated as a means to improve the cold sprayability of H13 tool steel powder. By adjusting starting powder size and shape as well as heat treatment conditions (maximum temperature, cooling rate, and atmosphere), cold spray of H13 powder went from virtually no deposition to the production of thick dense deposits with a deposition efficiency of 70%. Powder agglomeration, surface state, microstructure evolution, and softening are identified as key factors determining powder deposition efficiency and resulting deposit microstructure.

Characteristics of STS630 Based Metal Injection Molding Products on Powder Size, Sintering and Heat Treatment Conditions

2013 ◽  
Vol 372 ◽  
pp. 398-401
Author(s):  
Hee Jin Jeong ◽  
Hwan Kyun Yeo ◽  
Dae Yeol Bae ◽  
Je Hyun Kim ◽  
Dong Woo Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Injection Molding ◽  
Sintering Temperature ◽  
Processing Condition ◽  
Metal Injection Molding ◽  
Powder Size ◽  
Optimal Processing ◽  
Treatment Conditions ◽  
Debinding Process

This study proposes the research method to examine through experiment the mechanical properties of final products based on the size and sintering temperature of powder particle during STS630 powder based metal injection molding and heat treatment processing condition after the sintering. The feedstock for the injection was manufactured based on STS630 powder with the diameter of 7.0±1.0μm and 8.0±1.0μm and the sintering was carried at 2 temperature conditions of 1300°C and 1355°C after the injection and debinding process. Heat treatment conditions of sample after the sintering were divided into 2 types thus final samples of total 8 cases were manufactured. Then, the 5 types of mechanical properties test were conducted. Optimal processing conditions for MIM molding and heat treatment of STS630 powder could be established based on it.

Strengthening Mechanism of Additively Manufactured Cold Spray Al Deposits under Low Deposition Efficiency

2021 ◽  
Author(s):  
Ningsong Fan ◽  
Richard Jenkins ◽  
Pengfei Yu ◽  
Rocco Lupoi ◽  
Shuo Yin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cold Spray ◽  
High Strength ◽  
Deposition Efficiency ◽  
Strengthening Mechanism ◽  
Before And After ◽  
Novel Strategy ◽  
Al Coating ◽  
Wide Size Distribution

Abstract In this study, a novel strategy to manufacture high strength cold-sprayed Al coating by using powder with wide size distribution is proposed. The microstructure and mechanical properties of deposited coating sprayed at three typical impact velocities before and after heat treatment are investigated. Furthermore, the deposition and strengthening mechanisms of the coating sprayed at various impact velocities are clarified. The results show that the coating with higher density and mechanical properties can be successfully fabricated by cold spray at comparatively low particle impact velocity. The mechanical properties were enhanced with the contribution of heat treatment process. It is the in-process tamping effect induced by larger powder that results in the severe plastic deformation thus leads to densification and excellent mechanical properties of the cold-sprayed Al coating.

Metallurgical Approach for the Development of Heat Treatment Applied to 316L Stainless Steel Cold Spray Coatings

2021 ◽  
Author(s):  
Laury-Hann Brassart ◽  
Anne-Françoise Gourgues-Lorenzon ◽  
Jacques Besson ◽  
Francesco Delloro ◽  
David Haboussa ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cold Spray ◽  
Heat Treatments ◽  
Recrystallization Temperature ◽  
Scanning Calorimetry ◽  
Spray Coatings ◽  
Treatment Conditions ◽  
Long Time ◽  
Temperature Ranges ◽  
Sprayed Coatings

Abstract Industries developing cold-spray processes aim at producing dense and resistant coatings. Controlling microstructure and inter-particular fracture characteristics of sprayed coatings is essential to improve their properties. To do so; post-spraying heat treatment is a promising approach. This work addresses the development of such heat treatments and focuses on the analysis of recovery and recrystallization. Different heat treatment parameters were explored; namely; holding temperature and time; heating rate; and heating method. This approach revealed a competition between recrystallization and other microstructural evolution mechanisms; such as precipitation and porosity coalescence. An optimized heat treatment; allowing microstructural softening and adequate mechanical properties; was sought after. First; differential scanning calorimetry measurements applied to as-sprayed coatings enabled to identify recovery and recrystallization temperature ranges. Then; a variety of heat treatments was applied; involving long-time isothermal holdings as well as shorter cycles. Microstructure analysis and hardness measurements allowed making a first selection of treatment conditions.

On the defects of enamel coatings

2019 ◽  
pp. 145-150
Author(s):  
T. O. Soshina ◽  
V. R. Mukhamadyarovа
Keyword(s):  
Heat Treatment ◽  
Surface Tension ◽  
Electron Microscope ◽  
Enamel Coating ◽  
Surface Defects ◽  
Linear Expansion ◽  
Corrosion Properties ◽  
Treatment Conditions ◽  
Mechanical And Corrosion Properties ◽  
Coefficient Of Linear Expansion

The defects destroy the integrity of the enamel, and the paper examines the influence of the physical-mechanical and corrosion properties of frits and heat treatment on the defectiveness of the enamel coating. The surface defects were scanned by electron microscope. It has been established that the defectiveness of enamel coatings depends on the melting index, temperature coefficient of linear expansion, surface tension of the frits, and heat treatment conditions. When burning rate of the enamel coating decreases, the fine-meshed structure of the enamel changes, and the size of the defects decreases.

scholarly journals Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Energy Impact ◽  
Treatment Conditions ◽  
Mold Casting ◽  
Grade 3 ◽  
Good Agreement

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

Prediction of suitable heat treatment for H13 tool steels by application of thermal shock fatigue cycle

2021 ◽  
pp. 135065012110118
Author(s):  
Palani Karthikeyan ◽  
Sumit Pramanik
Keyword(s):  
Heat Treatment ◽  
Crack Initiation ◽  
Thermal Shock ◽  
Tool Steel ◽  
Treatment Method ◽  
Industrial Applications ◽  
Tool Steels ◽  
H13 Steel ◽  
H13 Tool Steel ◽  
Cyclic Treatment

In industry, thermally shocked components lead to early failures and unexpected breakdowns during production resulting in huge losses in profit. Thus, the present study investigates the as-received, hardened and hardened and nitrogen treated H13 tool steels subjected to a thermal shock gradient similar to the actual industrial applications. The thermal shock gradients were created by using an in-house-built thermal shock fatigue cyclic treatment machine. The effect of thermal shock fatigue cyclic treatments at 1000 and 2000 thermal shock cycles in hot and molten metal chambers was noticed. All the thermal shock fatigue cyclic-treated samples were analysed by hardness, X-ray diffraction, microscopy and magnetic tests. The interesting changes in hardness, distorted crystal structure and crack initiation were found to be different for differently treated H13 tool steel specimens. The molten aluminium was more prone to stick to the surface of as-received as well as hardened and nitrogen treated steel compared to the hardened H13 steel specimens, which would delay the crack initiation. The wear resistance properties of the hardened H13 steel specimens were found to be higher than as-received and hardened and nitrogen treated H13 steel specimens after thermal shock fatigue cyclic treatment. The loss in magnetic properties was significant for the hardened and hardened and nitrogen treated samples compared to as-received H13 tool steel specimens. Therefore, the present 1000 and 2000 thermal fatigue cycles for 30 s at 670 °C would be worthy to predict the proper heat treatment method to design the parameters as well as the life of die-casting components and to help in the economical production of casting.

Effect of copper incorporation on phase transformation behavior of electroless nickel–phosphorous coating and its effect on the tribological behavior

2020 ◽  
pp. 146442072098160
Author(s):  
Abhijit Biswas ◽  
Suman Kalyan Das ◽  
Prasanta Sahoo
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Tribological Behavior ◽  
Electroless Nickel ◽  
Two Phase ◽  
Microstructural Changes ◽  
Treatment Conditions ◽  
Heat Treated ◽  
Higher Temperature ◽  
Effect Of Copper

The microstructural changes of electroless Ni–P–Cu coating at various heat-treatment conditions are investigated to understand its implications on the tribological behavior of the coating. Coatings are heat-treated at temperatures ranging between 200°C and 800 °C and for 1–4 h duration. Ni–P–Cu coatings exhibit two-phase transformations in the temperature range of 350–450 °C and the resulting microstructural changes are found to significantly affect their thermal stability and tribological attributes. Hardness of the coating doubles when heat-treated at 452 °C, due to the formation of harder Ni3P phase and crystalline NiCu. Better friction and wear performance are also noted upon heat treatment of the coating at the phase transformation regime, particularly at 400 °C. Wear mechanism is characterized by a mixed adhesive cum abrasive wear phenomena. Heat treatment at higher temperature (600 °C and above) and longer duration (4 h) results in grain coarsening phenomenon, which negatively influences the hardness and tribological characteristics of the coating. Besides, diffusion of iron from the ferrous substrate as well as greater oxide formation are noticed when the coating is heat-treated at higher temperatures and for longer durations (4 h).

Effect of Heat Treatment Conditions on the Properties of Nanoporous Glasses Activated by Gold Nanoparticles

2021 ◽  
Author(s):  
G. Yu. Shakhgil’dyan ◽  
A. A. Mikhailov ◽  
T. O. Lipat’eva ◽  
K. I. Piyanzina ◽  
E. A. Kolesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Gold Nanoparticles ◽  
Treatment Conditions
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