scholarly journals Influence of Boron Additions and Heat Treatments on the Fatigue Resistance of CoCrMo Alloys

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1076 ◽  
Author(s):  
Marco A.L. Hernandez-Rodriguez ◽  
Rafael D. Mercado-Solis ◽  
Gerardo Presbítero ◽  
Diego E. Lozano ◽  
Gabriela M. Martinez-Cazares ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Fatigue Resistance ◽  
Base Alloy ◽  
Heat Treatment Condition ◽  
Heat Treated ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Joint Prostheses ◽  
Astm F75 ◽  
Cast Condition

Cobalt-based alloys are widely used in the manufacture of joint prostheses. In this study, the effect of boron additions and heat treatment on the ASTM F75 was evaluated by rotating bending fatigue. The boron ranged from 0.06–1 wt %. The alloys were tested in as-cast and heat-treated conditions. In the as-cast condition, the infinite life was observed at 380 MPa, improving to 433–615 MPa according to the amount of boron added. In the heat treatment condition, the fatigue resistance was improved only in the base alloy. The addition of 0.06 wt % boron and heat treatment led to the same resistance as in the as-cast condition. Adding large amounts of boron combined with heat treatment diminished the fatigue limit. The fracture analysis revealed primarily brittle behaviour with some ductile features even on the same sample; only the heat-treated alloy with 0.06 wt % boron was clearly ductile. This alloy also exhibited notably better toughness to crack propagation.

scholarly journals Influence of Different Heat Treatments on Torsional and Cyclic Fatigue Resistance of Nickel–Titanium Rotary Files: A Comparative Study

2020 ◽  
Vol 10 (16) ◽  
pp. 5604 ◽  
Author(s):  
Gianluca Gambarini ◽  
Andrea Cicconetti ◽  
Dario Di Nardo ◽  
Gabriele Miccoli ◽  
Alessio Zanza ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Fatigue Resistance ◽  
Cyclic Fatigue ◽  
Sem Analysis ◽  
Nickel Titanium ◽  
Torsional Resistance ◽  
Heat Treated ◽  
Torsional Test ◽  
Time To Fracture ◽  
Flexural Resistance

Protaper Universal (PTU), Protaper Gold (PTG) (Maillefer, Ballaigues, CH), EdgeTaper (ET), and EdgeTaper Platinum (ETP) (Albuquerque, NM, USA) were tested for both torsional and flexural resistance. The aim of the present study was to evaluate the influence of proprietary heat treatment on the metallurgical properties of the aforementioned instruments. Four groups of 30 different instruments (size 20.07) were tested, then divided into two subgroups of 15 instruments—one for the cyclic fatigue test in a curved canal (90°—2 mm radius) at 300 rpm and 2.5 Ncm. The time to fracture (TtF) and fragment length (FL) were recorded. The other subgroup was subjected to the torsional test (300 rpm, 5.5 Ncm). The torque to fracture and TtF were recorded. All the instruments underwent a SEM analysis. The heat-treated instruments showed a significantly higher fatigue resistance than the non-heat-treated instruments (p < 0.05). No significant differences were found in the torsional resistance between the ET and PTU, and the ETP and PTG. However, when comparing all the groups, the heat-treated instruments showed less torsional resistance. The improvement from heat treatment was mainly found in the cyclic fatigue resistance.

Industrial Heat Treatment of R-HPDC A356 Automotive Brake Callipers

2012 ◽  
Vol 192-193 ◽  
pp. 533-538 ◽  
Author(s):  
Levy Chauke ◽  
Heinrich Möller ◽  
Ulyate Andries Curle ◽  
Gonasagren Govender
Keyword(s):  
Heat Treatment ◽  
Tensile Properties ◽  
Automotive Industry ◽  
Laboratory Scale ◽  
Heat Treated ◽  
Die Cast ◽  
Eutectic Si ◽  
Hardness Increase ◽  
Cast Condition ◽  
Automotive Brake

Heat treatment of rheo-high pressure die cast (R-HPDC) A356 brake callipers has produced good mechanical properties on the laboratory scale. An industrial heat treatment is required to evaluate the applicability and conformance of the R-HPDC A356 brake callipers to the automotive industry. This research studied A356 brake callipers heat treated on the industrial scale with particular emphasis on the resulting microstructure, hardness and tensile properties. The eutectic Si-particle spheroidisation after solution heat treatment was achieved and observed with optical microscopy. A hardness increase from 64 to 100 Vickers was achieved from the as-cast condition to the industrially heat treated T6 condition. The heat treatment caused no significant variation in hardness and tensile properties from brake callipers within the same batch or from different batches. The yield and ultimate strengths of the industrial heat treated brake callipers were lower compared to the laboratory scale heat treatment properties, while the ductility increased, mainly due to quenching effects. Even though the industrial heat treated A356 brake callipers resulted in yield and ultimate tensile strengths lower than those achieved on a laboratory scale, they still exceeded the minimum specifications for gravity die cast A356 brake callipers.

Casting and Heat Treatment of Turbocharger Impellers Thixocast from Alloy 201

2012 ◽  
Vol 192-193 ◽  
pp. 556-561 ◽  
Author(s):  
Qiang Zhu ◽  
Stephen Midson ◽  
Chang Wei Ming ◽  
Helen V. Atkinson
Keyword(s):  
Heat Treatment ◽  
High Strength ◽  
Heat Treatment Condition ◽  
Hot Tearing ◽  
Alloy Casting ◽  
Heat Treated ◽  
Before And After ◽  
Optimum Heat ◽  
Semi Solid ◽  
Optimum Heat Treatment

Commercial semi-solid cast impellers are produced from Al-Si-Cu alloys heat treated to the T6 temper. The study described in this paper involved the identification of casting and heat treatment parameters to produce semi-solid processed turbocharger impellers from a silicon-free, higher strength 201 alloy. Casting parameters were identified which minimized hot tearing in the alloy 201 impellers. A series of heat treatment studies were performed to determine optimum heat treatment parameters. The T71 temper was identified as the preferred heat treatment condition to produce high strength as well as superior elongation. The results from mechanical property measurements conducted on the T71 heat treated impellers are reported. Optical and scanning electron microscopy (SEM) were also used to characterize the microstructure of alloy 201 impellers before and after heat treatment, and representative microstructures are presented.

Tensile and Fatigue Properties of Friction Stir Processed NiAl Bronze

2007 ◽  
Vol 539-543 ◽  
pp. 3751-3756 ◽  
Author(s):  
Christian B. Fuller ◽  
Murray W. Mahoney ◽  
William H. Bingel ◽  
Michael Calabrese ◽  
B. London
Keyword(s):  
Fatigue Resistance ◽  
Fatigue Testing ◽  
Processing Parameters ◽  
Fatigue Properties ◽  
Friction Stir ◽  
Refined Microstructure ◽  
Property Data ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Property Characterization

Friction stir processing (FSP) produced local microstructural refinement in cast Ni Al Bronze. The refined microstructure quality was evaluated with mechanical property characterization using monotonic tension and fatigue testing as a function of FSP raster patterns. Modifying the cast NiAl bronze with FSP resulted in a 140 - 172 % increase in yield strength, and a 40 - 57% increase in tensile strength. Changing the raster pattern from a linear to a rectangular spiral raster increased the tensile elongations by 40 - 134%. This increase in elongation was attributed to increased microstructural uniformity through the depth of the FSP raster. The ability to transfer FSP technology was demonstrated with consistent tensile property data produced by three different laboratories. Fatigue characterization (both uniaxial and rotating-bending fatigue) showed that FSP improved the cast NiAl bronze fatigue resistance. Both types of fatigue testing showed differences in fatigue resistance as a function of processing parameters.

Heat treatment effect on fatigue behavior of 3D-printed maraging steels

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tugce Tezel ◽  
Volkan Kovan
Keyword(s):  
Heat Treatment ◽  
Fatigue Test ◽  
Fatigue Behavior ◽  
Content Type ◽  
Bending Fatigue ◽  
Maraging Steels ◽  
Bending Fatigue Test ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Service Conditions

Purpose This study aims to reveal that fatigue life is improved using heat treatment in the rotational bending fatigue test, which determines the fatigue behavior closest to service conditions. Design/methodology/approach It is essential to know the mechanical behavior of the parts produced by additive manufacturing under service conditions. In general, axial stress and plane bending tests are used by many researchers because they are practical: the service conditions cannot be sufficiently stimulated. For this reason, the rotating bending fatigue test, which represents the conditions closest to the service conditions of a load-bearing machine element, was chosen for the study. In this study, the rotational bending fatigue behavior of X3NiCoMoTi18-9–5 (MS1) maraging steel specimens produced by the selective laser melting (SLM) technique was experimentally investigated under various heat treatments conditions. Findings As a result of the study, MS1 produced by additive manufacturing is a material suitable for heat treatment that has enabled the heat treatment to affect fatigue strength positively. Cracks generally initiate from the outer surface of the sample. Fabrication defects have been determined to cause all cracks on the sample surface or regions close to the surface. Research limitations/implications While producing the test sample, printing was vertical to the print bed, and various heat treatments were applied. The rotating bending fatigue test was performed on four sample groups comprising as-fabricated, age-treated, solution-treated and solution + age-treated conditions. Originality/value Most literature studies have focused on the axial fatigue strength, printing orientation and heat treatment of maraging steels produced with Direct Metal Laser Sintering (DMLS); many studies have also investigated crack propagation behaviors. There are few studies in the literature covering conditions of rotating bending fatigue. However, the rotating bending loading state is the service condition closest to modern machine element operating conditions. To fill this gap in the literature, the rotating bending fatigue behavior of the alloy, which was maraging steel (X3NiCoMoTi18-9–5, 1.2709) produced by SLM, was investigated under a variety of heat treatment conditions in this study.

scholarly journals A High Strength Nickel-Base Alloy With Improved Oxidation Resistance up to 2200 deg F

1968 ◽  
Vol 90 (1) ◽  
pp. 1-10
Author(s):  
W. J. Waters ◽  
J. C. Freche
Keyword(s):  
Heat Treatment ◽  
Weight Gain ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Base Alloy ◽  
High Strength ◽  
Nickel Base Alloy ◽  
Cast Material ◽  
Nickel Base ◽  
Cast Condition

A high strength nickel-base alloy has been developed which compares favorably in oxidation resistance with known high strength nickel-base alloys. The alloy, although basically a cast material, also possesses workability potential. After 310 hr exposure to air at 1900 deg F, the alloy had a weight gain of 1.8 mg/cm2. The total affected zone, oxidized material plus depletion zone, was 0.4 mil. This compares with a weight gain of 3.0 mg/cm2 and a total affected zone depth of 3.3 mils for Rene´ 41 after 100 hr exposure at 1900 deg F. In sheet form after 8 hr at 2200 deg F, its oxidation resistance was approximately the same as that of Rene´ 41 at 1900 deg F. Tensile strengths of the alloy after rolling and heat-treatment ranged from an average of 185,000 psi at 1400 deg F to 3000 psi at 2200 deg F. Maximum elongation was 55 percent and occurred at the latter temperature. At 1900 deg F, average tensile strength was 64,500 psi in the as-cast condition, and 54,000 psi after rolling and heat-treatment. Stress rupture data for low and intermediate stress levels were obtained. In the as-cast condition, use temperatures for 500, 100, and 10-hr life at 15,000 psi are 1815, 1895, and 2010 deg F, respectively. At 8000 psi and 2125 deg F, rupture life was 13 hr and compared favorably with some of the strongest known nickel and cobalt-base alloys. The very good high temperature oxidation resistance, good high temperature strength, and at least limited workability of this alloy suggest that it may be applicable for use in advanced gas turbine engine components.

Effects of semi-solid extrusion and heat treatment on the microstructure, mechanics, and wear resistance of SiC/High aluminum zinc-base alloy composites

2020 ◽  
Vol 34 (25) ◽  
pp. 2050261
Author(s):  
Yingwu Wang ◽  
Xiaoqing Zuo ◽  
Songjiang Ran ◽  
Yushun Ye ◽  
Jihua Tian
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Yield Strength ◽  
Base Alloy ◽  
Extrusion Temperature ◽  
Heat Treated ◽  
Semi Solid ◽  
High Aluminum

The effects of semi-solid extrusion temperature change, extrusion pressure, SiC content and T5 heat treatment on the microstructure, mechanical properties, and wear resistance of SiC particle strengthened high aluminum zinc-base alloy [Formula: see text] composites were studied. The results show that semi-solid extrusion broke the dendrites of [Formula: see text] composites, refined their grain structure, and improved particle aggregation. The density, hardness, yield strength, tensile strength and elongation of [Formula: see text] composites first increased and then decreased when the extrusion temperature and SiC content increased, and also increased when the extrusion pressure rose. The optimal extrusion temperature, pressure and SiC content are 475[Formula: see text], 15 MPa and 10 wt.%, respectively. T5 heat treatment further refined the crystalline grains and promoted [Formula: see text] and [Formula: see text] to precipitate as strengthening phases, which improve the mechanical properties and wear resistance of [Formula: see text] composites. Consequently, the hardness, yield strength, tensile strength and elongation of the heat-treated composites improved by 18.99%, 9.66%, 4.93% and 9.76%, respectively. The wear loss of the heat-treated composites reduced by 31.65% under a load of 1600 N and a rotational speed of 200 r/min compared with the as-cast composites.

Effect of Heat Treatment on Al-40Si Alloy Modified by Sr Addition

2011 ◽  
Vol 378-379 ◽  
pp. 108-111
Author(s):  
Wei Ke An ◽  
An Hui Cai ◽  
Xiang Fu Tan ◽  
Xiao Song Li ◽  
Yun Luo
Keyword(s):  
Heat Treatment ◽  
Optical Microscope ◽  
Heat Treatment Condition ◽  
Solution Temperature ◽  
Primary Si ◽  
Optimal Heat Treatment ◽  
Heat Treated ◽  
Optimal Value ◽  
The Matrix ◽  
Temperature Solution

The Al-40Si alloy modified by 1.0 wt% Sr addition was heat-treated using L9(34) orthogonal test. The mechanical properties were measured. The microstructures were analyzed using optical microscope. After heat treatment, the hardness decreases about one times. The eutectic matrix and primary Si phase are both refined. The primary Si phase is refined and homogeneously distributes in the matrix with the solution temperature and time increasing. The optimal heat treatment condition is that the solution temperature, solution time, aging temperature, and aging time are 550 °C, 18 hours, 200 °C, and 5 hours, respectively. In addition, the theoretical optimal value for the hardness is 20.6 HRC, which is coherent with the practical optimal value.

Effect of Radical Nitriding on Fatigue Strength of Ni-Base Superalloy

2009 ◽  
Vol 417-418 ◽  
pp. 205-208 ◽  
Author(s):  
Kazuhiro Morino ◽  
Norio Kawagoishi ◽  
K. Yamane ◽  
K. Fukada
Keyword(s):  
Fatigue Strength ◽  
Base Alloy ◽  
Compound Layer ◽  
Fatigue Tests ◽  
Bending Fatigue ◽  
Propagation Behavior ◽  
Initiation And Propagation ◽  
Rotating Bending Fatigue ◽  
Rotating Bending ◽  
Base Superalloy

In order to investigate the effect of nitriding on the crack initiation and propagation behavior of Ni-base super alloy, Alloy 718, rotating bending fatigue tests were carried out until 108 cycles at room temperature. By nitriding at 500°C for 12h, compound layer of about 5μm in thickness was formed and the initiation of a fatigue crack was strongly suppressed causing the increase in fatigue strength. A crack initiated in brittle manner at the compound layer in all of fractures. However the crack propagated in ductile manner controlled by the property of the base alloy. That is, there is no or little influence of nitriding on the crack growth rate of the alloy.

scholarly journals Evaluation of Vickers Hardness Number of Al-Si Alloy Under Heat Treated Conditions

2021 ◽  
Vol 10 (6) ◽  
pp. 222-227
Author(s):  
Jayasheel Kumar K A ◽  
◽  
C M Ramesha ◽  
Keyword(s):  
Heat Treatment ◽  
Vickers Hardness ◽  
Precipitation Hardening ◽  
Heat Treatment Condition ◽  
Vickers Hardness Number ◽  
Hardness Tester ◽  
Hardness Number ◽  
Heat Treated ◽  
Hardness Property ◽  
Property Assessment

The paper deal with the hardness property assessment of various Al-Si alloys under heat treated conditions. The tested specimens have the compositions of Si with percentages such as 12 18 and 24. The fabrication of the selected composition is carried out by melting the material to the melting temperature of around 800°C. The material is subjected to solutionised heat treatment for 3 hours at 500°C, 520°C and 535°C and quenched in water. Further aging is carried out at 155°C for 2 hours, 5 hours and 8 hours respectively for 500°C, 520°C and 535°C of solution heat treatment condition. The hardness property is evaluated using Vickers Hardness tester as per the standards of ASTM- E92. Thorough comparison of Vickers hardness number is performed among the as- cast and various heat treated environment. Desirable properties of alloy are observed at 520°C solutionised heat treatment & 5 hours of precipitation hardening at 155°C for 18% of Silicon composition. The hardness value decreases due to the increase in percentage of silicon and the values are observed.

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