จำนวน Repository ( 20 )

การตรวจสอบโครงสร้างและสมบัติทางกลของตะกรันอลูมิเนียม
การตรวจสอบโครงสร้างและสมบัติทางกลของตะกรันอลูมิเนียม

This research to examine the structure and mechanical properties of aluminum dross. A research project knowledge the aim is to study the microstructure and the mechanical properties of materials. The research is divided into two parts: 1 . preparation aluminum dross material and 2. to determine the structure and mechanical properties. The material must be washed in preparation contamination and dry then crushed and sifted to 200 mesh. Analyzed the microstructure with SEM which indicated the microstructure. The amount of alumina in aluminum dross grade No.0 has 8 0 percent with a powder aluminum dross grade No.1 is a hunk with crystalline alumina component 85 percent. Aluminum dross grade No. 2 which is a big hunk has crystalline alumina components 9 0 percent. Analysis results indicates that aluminum dross can be applied to other aspects such as to produce bulletproof vests and so on.

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การปรับปรุงสมบัติทางกลของพอลิแลกติกแอซิดด้วยเส้นใยปาล์มน้ำมัน
การปรับปรุงสมบัติทางกลของพอลิแลกติกแอซิดด้วยเส้นใยปาล์มน้ำมัน

This research work was to study the improvement of toughness of polylactic acid (PLA) and the cost reduction of raw material with addition of untreated and treated oil palm fiber (OPF). The detail of this work was divided into two parts. The first was to find the suitable condition for surface treatment of OPF with sodium hydroxide (NaOH). The second part was to study the effect of untreated and treated OPF contents on the mechanical properties of PLA. For surface treatment of OPF NaOH concentrations and immersion times were varied from 0 to 15 wt% and 0 to 30 min respectively. Aspect ratio (L/D) and surface of untreated and treated OPF were investigated by using optical microscope and scanning electron microscope (SEM) respectively. The result suggested that the most suitable condition for surface treatment of OPF was NaOH concentration of 10 wt% at immersion time of 20 min. Treated OPF was occurred microporous and had more rough as compare to untreated fiber. For the effect of untreated and treated OPF contents on the mechanical properties of PLA it was evaluated by tensile and impact testing. SEM was used for investigation of interfacial adhesion and fiber dispersion. The results showed that tensile modulus and impact strength tend to increase with adding 2.5 wt% OPF content and slightly changed at higher OPF content whereas ultimate tensile strength and elongation at break decreased with increasing fiber content. Surface treatment with NaOH led to enhancement of mechanical properties of composite due to improve interfacial adhesion and fiber dispersion.

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อิทธิพลของคุณสมบัติเชิงกลของใยสังเคราะห์ต่อคานปอซโซลานคอนกรีต
อิทธิพลของคุณสมบัติเชิงกลของใยสังเคราะห์ต่อคานปอซโซลานคอนกรีต

This research aims to study the possibility of steel fibers plastic fiber (polypropylene) fly ash and metakaolin mixed into the concrete. The concrete used in the research of the w / c 0.42 By 0.5 percent in the volume of steel fiber and poly propylene fiber in the amount of 0.25 percent by weight of the concrete. Concrete example of this test consisted of plain concrete(OPC).Concrete mixing materials pozzolan fly ash mixed plastics synthetic fibers of the type poly propylene fiber(FA/PP)concrete mixing materials pozzolan fly ash mixed plastics synthetic fibers of the type steel fibers (FA/ST) concrete mixing materials pozzolan meta kaolin mixed plastics synthetic fibers of kind polypropylene fiber(MK/PP) and concrete mixing materials pozzolan meta kaolin mixed plastics synthetic fibers of the typesteel fibers (MK/ST) by casting a cylindrical sample size 10 x 20 cm. Sample size 10x10x10 cm. cube and sample size 10x10x35 cm. beam. After 28 days and cure water concrete examples to test the strength of the pull compressive strength and flexural strength. And to test the movement of chloride through the concrete with Chloride Migration Test. Then bring the strength of the pull compressive strength flexural strength and the chloride permeability of concrete. Bringing concrete materials pozzolan mixed with synthetic fibers to develop the quality of concrete with improved efficiency and also reduces the porosity of the concrete. And permeability of chloride formed in the concrete (Only in landscape with the sea). The test can tell. Concrete mixing materials pozzolan with synthetic fibers to make a significant impact on the properties of concrete is improved as well. Depending on the type of polyester and the amount of material to pozzolan blended.

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การเปลี่ยนแปลงสมบัติทางกลของวัสดุผสมพีวีซีและผงขี้เลื่อยไม้ ภายใต้สภาวะการใช้งานที่มีความชื้น
การเปลี่ยนแปลงสมบัติทางกลของวัสดุผสมพีวีซีและผงขี้เลื่อยไม้ ภายใต้สภาวะการใช้งานที่มีความชื้น

This research work was to study the effect of moisture on mechanical properties of wood/polyvinylchloride composites (WPVC). WPVC specimens in ratio of PVC and wood (100:100 by weight) were prepared by using twin screw extruder. The water conditions for WPVC specimen immersion testing were varied for temperatures of 30-70 oC and specimen immersion time of 0-120 h. The moisture effect was investigated by measuring flexural properties and hardness of WPVC as comparing with case of PVC specimen. The result suggested that flexural modulus of WPVC tended to decrease with increasing time of water immersion and then remained unchanged at immersion time of more than 72 and 48 h for water temperature of 30 and 70 oC respectively. The decrease rate in flexural modulus enhanced when water temperature increased. Flexural modulus of PVC slightly changed with increasing both immersion time and water temperature. Flexural strength for both PVC and WPVC specimens were found the change at water temperature of 70 oC only. Flexural strength of PVC tended to slightly increase with increasing immersion time whereas flexural strength of WPVC slightly decreased with increasing immersion time. Hardness of PVC specimen in cases of both water temperature of 30 and 70 oC slightly increased with increasing immersion time. For WPVC hardness tended to decrease with increasing immersion time and water temperature.

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อิทธิพลของความเร็วรอบที่ส่งผลต่อสมบัติทางกลของการเชื่อมอะลูมิเนียมต่างชนิด ระหว่าง SSM7075 กับ SSM356 ด้วยการเชื่อมเสียดทาน
อิทธิพลของความเร็วรอบที่ส่งผลต่อสมบัติทางกลของการเชื่อมอะลูมิเนียมต่างชนิด ระหว่าง SSM7075 กับ SSM356 ด้วยการเชื่อมเสียดทาน

The objective of this research is to study how rotation speeds affect mechanical properties with friction welding between semi-solid metal 7075 aluminum alloys and semi-solid metal 356 aluminum alloys. The factor of interest is rotation speeds with different conditions at 800 1000 1200 1400 and 1600 rpm respectively. 1.8 millimeter for burn of length 30 seconds for welding time and clockwise rotation are set as a control constant condition for the entire experiment. After friction welding we found that different rotation speeds significantly affected mechanical properties of these alloys. At rotation speed 1400 rpm the maximum tensile strength is 122.24 MPa and the maximum hardness in welded zone is 140.5 HV. The microstructure size is 2.250 µm long and 2.144 µm wide. Its size in welded zone is practically small because of friction force. Moreover this friction force causes the mixture of MgZn2 and Mg2Si in welded zone.

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