材料导论

101For brasses, tin is the predominant alloying elements as substitutional impurity

102Refractory metals are those metals which have extremely low melting temperatures

103For some stainless steels, when heated to a certain temperature range (（）) for a sufficiently long time, these alloys become sensitized to intergranular attack

104Cathodic protection involves supplying electrons to the metal to be protected from an external source The external source maybe be an external（）or by（）

105Stress corrosion cracking (SCC) results from the combined action of an applied tensile stress and a corrosive environment

106Magnetostrictive materials can convert　energy into kinetic energy, or the reverse

107The magnetic shape memory effect results due to martensitic phase change to austenite phase at higher temperature

108Amorphous metals are non-crystalline, and have a glass-like structure Like common glasses, amorphous metals are electrical insulators

109All alloys that are not（）based, are called nonferrous metals

110Which of the following do not belong to non-ferrous metal?

111Cast iron can be classified into four categories: gray cast iron, white cast iron, nodular cast iron and（）cast iron

112Most cast irons have a chemical composition of（）percent carbon

113The predominant alloying element in stainless steel is（）, which concentration should be higher than 11 wt%

114（）is one of the principal alloying elements in stainless steels, and one major constituent in superalloys

115Metals are good conductors of both（）

116（）is believed the most glamorous metal in the world

117According to the composition, metal alloys are grouped into two classes:（）, and（）metals

118Stainless steels are divided into three classes on the basis of the predominant phase constituent of the microstructure:（）,（）, or（）

119uses cooling in still air？

120Some general corrosion protection techniques include material selection,（）,（）, and（）

121Compared with ferrous alloys, nonferrous metals are much lighter, and have lower conductivity

122The phase diagram contained only two components is known as binary diagrams

123Annealing and normalizing present a significant difference on the ductility of low carbon steels

124In corrosion process, the total rate of oxidation must equal the total rate of reduction

125Ceramics based primarily on the natural raw materials of clay and silicates are（）

126Advanced materials include　 , exhibit specialized properties

127The main source of quartz is

128The crystalline structure of Silicon carbide is　 with alternating Si and C atoms covalently bonded together

129Ceramics can be produced at　 than that of competing metal-alloy components

130Clay is a complex mixture of

131Sand consists of fine particles of quartz

132The term describing the density of ceramics that includes its porosity and both crystalline and noncrystalline phase is（）

133There are two factors influence the density of material

134The bulk density of complex geometric parts as well as their various porosities can be determined based on Archimedes principle

135Grinding is accomplished by confining the ceramic powder, this process can be called a　

136Sintering furnaces usually heat ceramic compacts externally by following thermal transfer

137A major problem in ceramic processing is achieving the same properties every time when a process is repeated

138Traditional processing for fabricating ceramic is

139The firing consolidates the particles and bonds the ceramic particles together permanently

140The most expensive glass is

141Amorphous materials do not have clearly defined freezing or melting points as do crystalline materials

142Following processing technique is not suitable for the biomicmickry or biomimetics

143Ceramics can be produced at than that of competing metal-alloy components

144Following material is not sorted to silicates

145（）refers to the network of pores that a liquid such as water can penetrate

146The main driving force in sintering process is

147Some flaws can occur at any of sintering stages, which consist of

148In cold step, the ceramic part is formed or shaped into a preform, which called

149（）is considered as glass former

150Slower cooling permits some crystallization in the process, we call it（）

151Nowadays, all of the polymers are synthesized artificially

152Saturated molecules-containing more than two functional groups cannot be used to produce polymers

153Number average molecular weights provide us some information related to（）

154The length or size of a polymer molecule can be quantified by（）

155The molecular weight distribution, PDI, could be a value near to 1, when polymers are produced by living or controlled polymerizations

156The activity of a growing radical can be destroyed by reaction with（）

157In condensation polymerization, two monomers, dimers, trimers, tetramers, or oligomers, can react with each other at any time

158Through controlled/living free-radical polymerization (CRP), molecular weight distribution could be narrowed greatly, and PDI could be near to 1

159Common polymers, such as PE, PP, PVC, PSt, nylon, and PET have linear structures

160The formation of cross-linked structures in synthetic rubbers is usually called vulcanization

161When the methyl group and H atom are located on opposite sides of the double bond, the polymer is a cis-isomer

162Materials in solid state may be（）

163Which ones of the following are correct?

164Which one (s) of the following is or are correct?

165Viscosity refers to the ability of a material to return to its original, initial size　shape once an external load or force is removed

166Totally elastic deformation occurs very quickly, and the strain is independent of time

167Semicrystalline polymer is formed in a temperature range from Tg to Tm

168Polycarbonate has a lower Tg than polyethylene

169PVC and PAN have a lower Tg than amorphous polypropylene

170Poly(1,4-cis-butadiene) has a higher Tg than Poly(1,4-trans-butadiene) because the cis -form reduces the energy barrier for rotation of adjacent bonds

171Examples of common thermoplastic polymers include（）

172Thermoplastics are mainly prepared by addition polymerization

173Thermoset polymers are generally harder and stronger than thermoplastics and have better dimensional stability

174Thermosetting polymers have the distinct advantage of being chemically and thermally resistant materials used in many high-performance applications

175Fillers are most often added to improve tensile strength, and（）

176Most polymers are flammable in their pure form, except（）

177Additives are external substances purposely added to change properties of polymers or resins

178Polyethylene pipes can be processed by　

179Which forming technique(s) could be employed to process thermosetting plastics?

180Natural rubber is a kind of　

181Which of following properties are the problem natural rubber in practical application?

182After vulcanization, there are still many carbon-carbon double bonds in the molecular chains of natural rubber

183An elastomer with great resistance to gas permeation can serve as inner tubes, gas hoses, tubing

184The sidewall rubber of tire is

185Neoprene rubber is widely used to prepare divers suit and soles, based on its special properties of

186SBR has a lower hysteresis than polyisoprene

187Silicon rubber also has many reactive points in the molecular chains, which is same as polyisoprene and polybutadiene

188Which of the following property would thermoplastic elastomer have over natural rubber and synthetic rubber?

189is an elastomer has physical cross-links in the network structure

190can be employed as the physical crosslinking structure in thermoplastic elastomer

191There is a chemical cross-linking in the rubber network of thermoplastic rubbers

192For the molecular weight distribution, which one of the followings is not correct?

193The fundamental reactions involved in addition polymerization are（）

194When an improved tensile loading is applied, crystallinity of natural rubber would

195Using terephthalic acid and ethylene glycol, and by the reaction of carboxyl and hydroxyl groups,（）is synthesized

196Monomers used for producing polymers should be（）

197Polymers with high molecular weights have（）

198Usually，polymerization includes（）, based on the mechanism involved in forming polymers

199Usually, polymers have the structures of（）, and various isomeric configurations

200The repeating units on the copolymer chain may be arranged in various sequences along the backbone chain, including:

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