Damping Capacity of Metallic Materials for Automotive Industry

2017 ◽  
Vol 750 ◽  
pp. 164-167
Author(s):  
Radu Cristian Crăciun ◽  
Sergiu Stanciu ◽  
Nicanor Cimpoeşu ◽  
Ramona Cimpoeşu ◽  
Vasile Manole

New requests from the automotive industry suppose to apply new materials with mechanical resistance to heat and vibrations and also with low weight. In order to replace plastic materials with high damping capacity a viable solution can be the metallic materials with sufficient internal friction to transform the external mechanical energy in thermal energy without affecting the microstructure or the mechanical properties of the metallic materials. In automotive applications an important role, especially in low velocity impacts, are the bumper elements. In this article possibility of copper-based shape memory alloys to fulfill the damping necessity of metallic materials is analyzed. Dynamic - mechanical analyze of few copper based shape memory alloys is realized and the results compared to proposed a better solution of Cu-based shape memory alloy for damping materials applications. The damping capacity difference between martensite and austenite like phases is also analyzed.

2017 ◽  
Vol 907 ◽  
pp. 61-66 ◽  
Author(s):  
Radu Cristian Crăciun ◽  
Sergiu Stanciu ◽  
Victor Geanta ◽  
Ionelia Voiculescu ◽  
Ramona Cimpoeşu ◽  
...  

High damping capacity materials present an increased interest in many applications were vibration and noise reduction is absolutely necessary. Metallic materials with a high internal friction (IF) are becoming valuable because of them usual mechanical properties that fulfill the damping capacity in applications. Some of the shape memory alloys present a huge damping capacity during the solid state transformation (M↔A) based on the re-orientation and accommodation of the material structure. Iron based shape memory alloy present the best advantages for industrial application as dumpers in different areas. Beside civil construction domain these materials can cover also applications in automotive industry as shock impact absorbers for low velocities as protection for engine parts and also for noise reduction. By these means in this article we analyze FeMnSi+Al alloy with a new chemical composition obtained through classical melting method in Ar controlled atmosphere.


2013 ◽  
Vol 371 ◽  
pp. 368-372 ◽  
Author(s):  
Nicanor Cimpoeşu ◽  
Adela Ioana Ursanu ◽  
Sergiu Stanciu ◽  
Ramona Cimpoeşu ◽  
Boris Constantin ◽  
...  

Shape memory alloys (SMAs) are commonly used in micro-electro-mechanical systems (MEMS). Having the unique shape memory, super-elastic affects and now damping capacity SMAs have become an important smart material for a broad range of engineering applications in last years. Copper based SMAs are promising alloys, based on the obtaining price and good characteristic properties. Shape memory alloys as thin films are used for fast actuation in applications due to their high surface to volume ratio comparing to bulk SMAs. In this paper two shape memory alloys based on copper, proposed as targets in different deposition processes to obtain MEMS and with different chemical composition, are analyzed through scanning electrons microscope (SEM), XRD and EDAX considerations after water quenching and recovery heat treatments. The martensite variants are dimensioned and 3D aspects are also analyzed for both metallic materials. The metallic phases obtained after heat treatment are determined and compare in both thermal influenced cases.


2016 ◽  
Vol 845 ◽  
pp. 77-82
Author(s):  
Vladimir V. Khovaylo ◽  
Valeria Rodionova ◽  
Sergey Taskaev ◽  
Anna Kosogor

Intermetallic alloys and compounds undergoing diffusionless solid–solid phase transformations are an important class of high-damping materials. Some representatives of these alloys and compounds also possess good magnetic properties. For such materials, a combination of the magnetoelastic coupling and a high mobility of the martensitic variants can bring about new features of the internal friction and allows one to control the damping capacity by an external magnetic field. Here we review damping properties of magnetically ordered shape memory alloys.


Author(s):  
Jan Van Humbeeck ◽  
Johannes Stoiber ◽  
Luc Delaey ◽  
Rolf Gotthardt

2014 ◽  
Vol 657 ◽  
pp. 392-396
Author(s):  
Adela Ursanu Dragoş ◽  
Sergiu Stanciu ◽  
Nicanor Cimpoeşu ◽  
Mihai Dumitru ◽  
Ciprian Paraschiv

Entire or partial loss of function in the shoulder, elbow or wrist represent an increasingly common ailment connected to a wide range of injuries or other conditions including sports, occupational, spinal cord injuries or strokes. A general treatment of these problems relies on physiotherapy procedures. An increasing number of metallic materials are continuously being developed to expect the requirements for different engineering applications including biomedical field. Few constructive models that can involve intelligent materials are analyzed to establish the advantages in usage of shape memory elements mechanical implementation. The shape memory effect, superelasticity and damping capacity are unique characteristics at metallic alloys which demand careful consideration in both design and manufacturing processes. The actual rehabilitation systems can be improved using smart elements in motorized equipments like robotic systems. Shape memory alloys, especially NiTi (nitinol), represent a very good alternative for actuation in equipments with moving dispositive based on very good actuation properties, low mass, small size, safety and user friendliness. In this article the actuation and the force characteristics were analyzed to investigate a relationship between the bending angle and the actuation real value.


2012 ◽  
Vol 78 ◽  
pp. 31-39 ◽  
Author(s):  
Ausonio Tuissi ◽  
Paola Bassani ◽  
Carlo Alberto Biffi

Foams and other highly porous metallic materials with cellular structures are known to have many interesting combinations of physical and mechanical properties. That makes these systems very attractive for both structural and functional applications. Cellular metals can be produced by several methods including liquid infiltration of leachable space holders. In this contribution, results on metal foams of Cu based shape memory alloys (SMAs) processed by molten metal infiltration of SiO2 particles are presented. By using this route, highly homogeneous CuZnAl SMA foams with a spherical open-cell morphologies have been manufactured and tested. Morphological, thermo-mechanical and cycling results are reported.


2006 ◽  
Vol 319 ◽  
pp. 33-38 ◽  
Author(s):  
I. Yoshida ◽  
Kazuhiro Otsuka

Low frequency internal friction of Ti49Ni51 binary and Ti50Ni40Cu10 ternary shape memory alloys has been measured. The effect of solution and aging heat treatments on the damping property was examined. The temperature spectrum of internal friction for TiNi binary alloy consists, in general, of two peaks; one is a transition peak which is associated with the parent-martensite transformation and is rather unstable in a sense that it strongly depends on the frequency and decreases considerably when held at a constant temperature. The other one is a very high peak of the order of 10-2, which appears at around 200K. It appears both on cooling and on heating with no temperature hysteresis, and is very stable. The behavior of the peak is strongly influenced by the heat treatments. The trial of two-stage aging with a purpose of improving the damping capacity has been proved unsatisfactory. TiNiCu has a very high damping, the highest internal friction reaching 0.2, but by quenching from very high temperature, say 1373K, the damping is remarkably lowered. For the realization of high damping the quenching from a certain temperature range around 1173K seems the most preferable condition.


1993 ◽  
Vol 115 (1) ◽  
pp. 129-135 ◽  
Author(s):  
C. Liang ◽  
C. A. Rogers

Shape memory alloys (SMAs) have several unique characteristics, including their Young’s modulus-temperature relations, shape memory effects, and damping characteristics. The Young’s modulus of the high-temperature austenite of SMAs is about three to four times as large as that of low-temperature martensite. Therefore, a spring made of shape memory alloy can change its spring constant by a factor of three to four. Since a shape memory alloy spring can vary its spring constant, provide recovery stress (shape memory effect), or be designed with a high damping capacity, it may be useful in adaptive vibration control. Some vibration control concepts utilizing the unique characteristics of SMAs will be presented in this paper. Shape memory alloy springs have been used as actuators in many applications although their use in the vibration control area is very recent. Since shape memory alloys differ from conventional alloy materials in many ways, the traditional design approach for springs is not completely suitable for designing SMA springs. Some design approaches based upon linear theory have been proposed for shape memory alloy springs. A more accurate design method for SMA springs based on a new nonlinear thermomechanical constitutive relation of SMA is also presented in this paper.


2016 ◽  
Vol 101 ◽  
pp. 79-88 ◽  
Author(s):  
Vicenç Torra ◽  
Sara Casciati ◽  
Michele Vece

The use of Shape Memory Alloys in dampers devices able to reduce the wind, rain or traffic induced oscillations in stayed cables is well represented in the literature. An analysis realized on standard cables at existing facilities shows the reliable efficiency of the SMA wire in damping oscillations. Such studies also provide tools to build the SMA dampers and to account for the effects of the external temperature in the SMA. The particular study reported in this paper focuses on a critical discussion on the relation between the wire diameter and macroscopic behavior and external temperature effects. The damping requires the absorption of the mechanical energy and its conversion to heat via the action of hysteresis cycles. The study was realized on wires of different diameters. In particular, the study centers on wires of diameter 0.2, 0.5 and 2.46 mm. The flat cycles showed by the thin wires (i.e., diameter 0.2 and 0.5 mm) and the non-classical S-shaped cycles of wires of diameter 2.46 mm establish clear differences of the response under external summer-winter temperature actions. Depending of the room temperature and SMA composition, a complete flat transformation in thin wires requires stresses, in general, near 300-400 MPa. A complete transformation for an S-shaped cycle need stresses as higher as 600 MPa. The analysis of the behavior of these wires under the action of warm temperatures in summer and cold temperatures in winter, suggests that thin wires lose their pseudo-elastic state in winter. The S-shaped permits positive working in extended temperature domain and a supplementary investigation establishes that S-shaped can be increased by strain aging. The hysteretic behavior in S-shaped permits practical working under external temperatures as applications in bridges require. From a fundamental point of view, the flat cycles are coherent with the classical treatment of the SMA as a first order phase transition but the S-shaped can be considered associated to an anomaly in heat capacity.


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