Investigation of the mechanical properties of AlSi9Cu3(Fe)/MWCNT nanocomposites prepared by HPDC

Abstract

In this research, an often-used high-pressure die-casting (HPDC) AlSi9Cu3(Fe) alloy was chosen as the matrix for an Al-alloy/MWCNT nanocomposite material that could be, in the case of targeted mechanical properties, used for the production of lighter car parts. In the industrial experiment, nanocomposite samples were prepared by a HPDC machine from a base AlSi9Cu3(Fe) alloy with three different mass ratios of MWCNTs placed on two different positions inside the casting machine. The structure and thermal stability of the used MWCNTs were visually confirmed by scanning electron microscopy (SEM). The microstructural and metallographic properties were studied using an optical microscope. The mechanical properties (tensile strength, elongation at break and hardness) were investigated using a universal testing machine and a Vickers hardness tester. The experimental results of this research showed that the HPDC-prepared Al-alloy matrix nanocomposite material had significantly changed mechanical properties even with small MWCNT contents. The elongation at break and the tensile strength of the Al-alloy/MWCNT nanocomposite were increased in comparison with the base alloy. The finest microstructure was shown by samples with 0.05 w/% MWCNTs, which was in correlation with the most significant change in the mechanical properties. Keywords: metal-matrix nanocomposites, AlSi9Cu3(Fe) alloy, multi-walled carbon nanotubes (MWCNT), high-pressure die casting (HPDC) Avtorji opisujejo raziskavo izdelave nanokompozitnega materiala s kovinsko osnovo iz zlitine AlSi9Cu3(Fe). Za oja~itveno fazo so uporabili ve~stenske ogljikove nanocev~ice (MWCNT). Za izdelavo kompozita so uporabili visokotla~no brizganje taline v kovinsko orodje oz. deljivi model (HPDC). Ta postopek se najbolj pogosto uporablja za izdelavo lahkih avtomobilskih delov s specifi~nimi mehanskimi lastnostmi. Izvajali so industrijske preizkuse na HPDC stroju in pri tem uporabili kovinsko talino AlSi9Cu3(Fe) s tremi razli~nimi dodatki MWCNT, ki so jih postavili na dve razli~ni mesti v votlini orodja. Strukturno in termi~no stabilnost uporabljenih MWCNT so potrdili s preiskavo ulitkov pod vrsti~nim elektronskim mikroskopom (SEM). Nadalje so izvedli {e metalografske preiskave mikrostrukture pod opti~nim mikroskopom. Mehanske lastnosti izdelanih materialov, natezno trdnost in raztezek po prelomu, so dolo~ili na univerzalnem trgalnem stroju, medtem ko so trdoto dolo~ili na standardnem Vickersovem merilniku. Eksperimentalni rezultati te preiskave so pokazali, da so se mehanske lastnosti s postopkom HPDC izdelanega nanokompozita na osnovi Al zlitine znatno spremenile`e pri dodatku dokaj malih koli~in MWCNT. Natezna trdnost in raztezek po prelomu nanokompozita MWCNT/Al-zlitina sta v primerjavi z osnovno Al zlitino narasla. Najbolj drobnozrnato mikrostrukturo so imeli vzorci z dodatkom 0,05 masnih dele`ev MWCNT, kar se je ujemalo z najve~jo spremembo mehanskih lastnosti. Klju~ne besede: nanokompoziti s kovinsko osnovo, zlitina AlSi9Cu3(Fe), ve~stenske ogljikove nanocev~ice (MWCNT), visok...

Low- and High-Pressure Casting Aluminum Alloys: A Review

“…Table 3 represents some of the mechanical properties of this alloy defined in the standard NP-EN 1706 (2000) [10] and some results from different studies [20][21][22].…”