scholarly journals Influence of Deep Rolling and Induction Hardening on Microstructure Evolution of Crankshaft Sections made from 38MnSiVS5 and 42CrMo4

2021 ◽  
Vol 76 (3) ◽  
pp. 175-194
Author(s):  
A. Fischer ◽  
B. Scholtes ◽  
T. Niendorf
Keyword(s):  
Process Parameters ◽  
Microstructure Evolution ◽  
Surface Hardening ◽  
Qualitative Evaluation ◽  
Induction Hardening ◽  
Deep Rolling ◽  
Automotive Components ◽  
Hardening Treatment ◽  
Steel Grades ◽  
Definition Of

Abstract In order to improve properties of complex automotive components, such as crankshafts, in an application-oriented way, several surface hardening treatments can be applied. Concerning the material performance the definition of adequate process parameters influences the resulting surface properties and, thus, the effectiveness of surface hardening treatments. To analyze most relevant process-microstructure-property relationships, the present paper reports results obtained by two different well-established surface hardening procedures, i. e. deep rolling as a mechanical treatment and induction hardening as a thermal treatment. For each hardening process widely used crankshaft steel grades, i. e. a medium carbon 38MnSiVS5 microalloyed steel and a quenched and tempered 42CrMo4 were selected and thoroughly characterized upon processing, using equal parameter settings. The results reveal that deep rolling in contrast to induction hardening proves to be a less sensitive surface layer treatment with regard to small differences in the initial microstructure, the chemical composition and the applied process parameters. Differences in microstructure evolution with respect to the applied surface hardening treatment are studied and discussed for the highly stressed fillet region of automotive crankshaft sections for all conditions. In this context, high-resolution SEM-based techniques such as EBSD and ECCI are proven to be very effective for fast qualitative evaluation of induced microstructural changes.

scholarly journals Analysis of the Downscaling Effect and Definition of the Process Fingerprints in Micro Injection of Spiral Geometries

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 335 ◽  
Author(s):  
Antonio Luca ◽  
Oltmann Riemer
Keyword(s):  
Correlation Analysis ◽  
Process Parameters ◽  
Cross Sections ◽  
Mass Production ◽  
Process Window ◽  
Response Variable ◽  
Process Indicators ◽  
Flow Length ◽  
Definition Of ◽  
Microinjection Moulding

Microinjection moulding has been developed to fulfil the needs of mass production of micro components in different fields. A challenge of this technology lies in the downscaling of micro components, which leads to faster solidification of the polymeric material and a narrower process window. Moreover, the small cavity dimensions represent a limit for process monitoring due to the inability to install in-cavity sensors. Therefore, new solutions must be found. In this study, the downscaling effect was investigated by means of three spiral geometries with different cross sections, considering the achievable flow length as a response variable. Process indicators, called “process fingerprints”, were defined to monitor the process in-line. In the first stage, a relationship between the achievable flow length and the process parameters, as well as between the process fingerprints and the process parameters, was established. Subsequently, a correlation analysis was carried out to find the process indicators that are mostly related to the achievable flow length.

scholarly journals Effect of primary silicon crystals on the fluidity of eutectic and hypereutectic Al-Si alloys in lost foam casting

2021 ◽  
Author(s):  
Shailesh Kamble
Keyword(s):  
Process Parameters ◽  
Metal Flow ◽  
Primary Silicon ◽  
Lost Foam Casting ◽  
Minor Role ◽  
Automotive Components ◽  
Silicon Crystals ◽  
A Minor ◽  
Lost Foam

The hypereutectic Aluminum-Silicon (Al-Si) Alloys are gaining impetus in the automotive components, mainly due to their wear resistance. This property in these alloys is derived from the primary silicon crystals. However, there are unique metal flow and mold filling problems associated with hypereutectic Al-Si alloys in Lost Foam Casting (LFC). This investigation is a pioneering work undertaken to gain a better understanding of the role of primary silicon crystals and other phases in the LFC of hypereutectic Al-Si alloys. Time-temperature and first derivative curves were used to determine velocity of metal flow and to calculate solid fractions. Process parameters such as superheat, gating design and alloy composition were manipulated to change the morphology of primary silicon crystals. Microscopy and image analysis of castings enabled study of precipitated particles. Solidification, interlocking and melt sluggishness of precipitated particles significantly influenced fluidity, and the routine process parameters played a minor role.

Heat Treatment

2013 ◽  
pp. 271-324
Keyword(s):  
Heat Treatment ◽  
Surface Hardening ◽  
Precipitation Hardening ◽  
Temper Embrittlement ◽  
Induction Hardening ◽  
Heat Treatments ◽  
Metals And Alloys ◽  
Continuous Cooling Transformation Diagrams ◽  
Transformation Diagrams ◽  
Carbon System

Abstract This chapter discusses the processes used in manufacturing to thermally alter the properties of metals and alloys. It begins with a review of the iron-carbon system, the factors that affect hardenability, and the use of continuous cooling transformation diagrams. It then explains how various steels respond to heat treatments, such as annealing, normalizing, spheroidizing, tempering, and direct and interrupted quenching, and surface-hardening processes, such as flame and induction hardening, carburizing, nitriding, and carbonitriding. It also addresses the issue of temper embrittlement and discusses the effect of precipitation hardening on aluminum and other alloys.

scholarly journals Design Space and QbD Approach for Production of Drug Nanocrystals by Wet Media Milling Techniques

Pharmaceutics ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 104 ◽  
Author(s):  
Leena Peltonen
Keyword(s):  
Process Parameters ◽  
Design Space ◽  
Milling Process ◽  
Production Chain ◽  
Media Milling ◽  
Process Understanding ◽  
Poorly Soluble ◽  
Critical Process Parameters ◽  
Input Variables ◽  
Definition Of

Drug nanocrystals are nanosized solid drug particles, the most important application of which is the improvement of solubility properties of poorly soluble drug materials. Drug nanocrystals can be produced by many different techniques, but the mostly used are different kinds of media milling techniques; in milling, particle size of bulk sized drug material is decreased, with the aid of milling beads, to nanometer scale. Utilization of Quality by Design, QbD, approach in nanomilling improves the process-understanding of the system, and recently, the number of studies using the QbD approach in nanomilling has increased. In the QbD approach, the quality is built into the products and processes throughout the whole production chain. Definition of Critical Quality Attributes, CQAs, determines the targeted final product properties. CQAs are confirmed by setting Critical Process Parameters, CPPs, which include both process parameters but also input variables, like stabilizer amount or the solid state form of the drug. Finally, Design Space determines the limits in which CPPs should be in order to reach CQAs. This review discusses the milling process and process variables, CPPs, their impact on product properties, CQAs and challenges of the QbD approach in nanomilling studies.

Effect of process parameters on the microstructure evolution of laser surface quenched Ni-Al bronze

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040029
Author(s):  
Zhenbo Qin ◽  
Da-Hai Xia ◽  
Yida Deng ◽  
Wenbin Hu ◽  
Zhong Wu
Keyword(s):  
Grain Boundary ◽  
Process Parameters ◽  
Microstructure Evolution ◽  
Laser Scanning ◽  
Threshold Value ◽  
Laser Surface ◽  
High Rate ◽  
Fine Grained ◽  
Surface Quenching ◽  
Overlap Ratio

Laser surface quenching technology was used to modify the surface microstructure of as-cast Ni-Al bronze (NAB). The modified microstructure was studied by scanning electron microscopy (SEM), and the effect of laser process parameters on microstructure evolution was investigated. It was found that a fine-grained zone with fully [Formula: see text] phase microstructure formed on the surface of NAB. The depth of the fine-grained zone increased with the increase of laser power, and surface melting occurred when the power reached a threshold value. Laser scanning at a low rate caused the coarsening of grain boundary, while too high rate led to incomplete quenching. Spot overlap ratio determined the microstructure of the superimposed area, and unsuitable ratio would cause bulky [Formula: see text] precipitation at the grain boundary or incomplete transformation from [Formula: see text] phase to [Formula: see text] phase.

Sign in / Sign up

Export Citation Format

Share Document