Search

Different weight ratios of cerium (0.5, 1 and 2 wt.%) were produced in a controlled atmosphere by High Pressure Die Cast method to Mg-6Al-0.3Mn-1Sn alloy. The influence of cerium on microstructure and high-temperature mechanical properties was investigated. The microstructure study revealed that the main alloy contains intermetallic phases such as alpha-Mg, beta- Mg17Al12, Mg2Sn and Al11Ce3. The hardness values of the alloys were increased with the addition of 0.5%, 1 and 2 cerium. With the addition of 0.5 wt.% Ce, the yield strength increased to 145 MPa. With the addition of 2 wt.% of Ce, it was found to be 160 MPa with an increase of 14%. Tensile strength was obtained as 190 MPa. Elevated temperature tensile test was carried out at 120 degrees C, 180 degrees C and 240 degrees C, to all the alloys. It was found that increased Ce ratio increased the high-temperature mechanical strength. At 120 degrees C, the highest tensile and yield strength values were obtained with 159 MPa and 147 MPa, respectively, in the alloy with 2% wt. cerium added. In the tensile test performed at 180 degrees C, the highest tensile and yield strength were measured as 91 MPa and 77 MPa, respectively. The operating temperature of Mg alloys produced industrially by HPDC has a significant effect on mechanical properties. High operating temperatures reduce mechanical properties. However, the mechanical properties at high test temperatures were increased by the addition of Ce metal to the AM60-1Sn-XCe alloy produced with HPDC.

In the present study, the effect of an La alloying element with different quantities (1, 3 and 5 wt.-%) on the microstructure, mechanical and dry sliding wear properties of Mg- 3Al-3Sn-3Sb alloy was investigated. The wear tests were done on the alloys using pin on-disk equipment against a 4140 steel disc as counterpart under three different sliding velocities of 0.3, 0.6 and 1.2 ms-1 and four different loads of 5, 10, 20 and 40 N. The microstructural results showed that the new intermetallic phases (La5Sn3 and LaSnSb2) were formed with addition of La to the main alloy. Also, it was observed that the hardness of the Mg-3Al-3Sn-3Sb alloy was raised with increasing La addition. Furthermore, the tensile properties of the Mg-3Al-3Sn-3Sb alloy improved with rising La content at room and elevated temperature. The wear rates of the alloys increase with increasing of the sliding speed and load. In addition to this, the wear rate of the Mg-3Al-3Sn-3Sb alloy was found to be higher than that of the La content alloys for all test conditions.

Purpose: In this study, it was produced with HPDC by adding Cerium rare element to Mg-4Sb-2Al alloy. The effect of Ce on mechanical properties was explained by the theories of microstructural transformation and new phase formation. Theory and Methods: Mg-4Sb-2Al alloy, which is a new generation alloy in Mg alloys, was developed and the existing properties were further improved by adding the alloy RE (Rare Element). In the selection of additive elements of the basic alloying element, Mg-4Sb-2Al alloy, its suitability to pressure casting (HPDC) technique, which is one of the most important production techniques especially for light metal casting industry, has been taken into consideration. Sb and Al elements as the alloying element were added to the Mg alloy and the main alloying element was produced. In the selection of these elements, approaches such as basic material science criteria, favorable flow and porosity properties for casting, compliance with strength enhancement criteria were taken as basis. 0.5wt.% -2wt.% Ce was added to the alloy and metallurgical investigations were carried out. Results: The addition of Ce was chosen between wt. 0.5% and wt. 2% and the optimum Ce ratio was determined. It was understood that the added Ce also acts as a grain refiner and a new intermetallic CeSb was formed at the grain boundaries. wt. 1% Ce added alloy had a tensile strength of 164-168 MPa and an elongation of 13%. In the amount of 2% Ce added, the tensile strength of the alloy produced was found to be 16%, measured at values between 163-167 MPa. Conclusion: It has been concluded that if the elongation criteria of Mg-4Sb-2Al alloys produced with HPDC are 12%, the alloy with 1% Ce addition will be an ideal engineering alloy on the basis of tensile strength, hardness and economy., Bu çalışmada Mg-4Sb-2Al alaşımına, ağırlıkça% 0,5, 1, 2 oranlarında Ce (seryum) elementi ilavesinin etkisi incelenmiştir. Döküm prosesi olarak yüksek basınçlı kokil kalıba döküm yöntemi kullanılmıştır. Üretilmesi planlanan ürünler direk olarak çekme ve darbe numunesi şeklinde üretilmiştir ve çekme numuneleri yarı endüstriyel pilot ölçekli numuneleri temsil etmektedir. Üretilen numunelerin mekanik özelliklerini tespit etmek için çekme deneyleri, sertlik deneyleri, metalurjik ilişkiyi tespit etmek için ise metalografik inceleme, SEM ve XRD incelemeleri yapılmıştır. İlave edilen Ce oranına bağlı olarak mekanik özellikler artmıştır. Bu sonuçlara göre Mg3Sb2, Mg12Ce, CeSb ve Mg fazlarının varlığı tespit edilmiştir. İlave edilen Ce oranının artmasına bağlı olarak yeni bir faz olan CeSb fazının şiddeti artmıştır. CeSb ve Mg3Sb3 intermetalik fazlarının tane sınırlarında biriktiği anlaşılmıştır. Tane sınırlarında çubuğumsu bir şekilde birikim gösteren bu yapılar, dislokasyon hareketini engellemek ve ince taneli bir yapı oluşturmak sureti ile çekme mukavemetini ve sertlik değerlerini artırmıştır. Çekme mukavemeti değerleri %0,5 Ce, %1 Ce, %2 Ce ilave edilen alaşımlar için sırası ile 145-148 MPa, 164-168 MPa, 163-167 MPa aralığında, uzama yüzdeleri ise sırası ile %12,%13 ve %16 olarak tespit edilmiştir. Ce ilavesi ile sertlik değeri 48 BHN’den 54 BHNe’ye artmıştır.