Cemented Carbides MCQs : Here you will find MCQ Questions related to "Cemented Carbides" in Powder Metallurgy. These Cemented Carbides MCQ Questions Will help you to improve your Powder Metallurgy knowledge and will prepare you for various Examinations like Competitive Exams, Placements, Interviews and other Entrance Exmaniations
Question 1
Cemented carbide is a soft material used extensively as cutting tool material.
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : B
Explanation: Cemented carbide is a hard material used extensively as cutting tool material, as well as other industrial applications.
Question 2
Cemented carbides commonly use?
A. tungsten carbide
B. titanium carbide
C. tantalum carbide
D. All of the above
View Answer
Ans : D
Explanation: Cemented carbides commonly use tungsten carbide (WC), titanium carbide (TiC), or tantalum carbide (TaC) as the aggregate.
Question 3
The first cemented carbide developed was tungsten carbide introduced in?
A. 1925
B. 1926
C. 1927
D. 1928
View Answer
Ans : C
Explanation: The first cemented carbide developed was tungsten carbide (introduced in 1927) which uses tungsten carbide particles held together by a cobalt metal binder.
Question 4
The process of combining the carbide particles with the binder is referred to as ?
A. HIP
B. SP
C. EC
D. QIS
View Answer
Ans : A
Explanation: The process of combining the carbide particles with the binder is referred to as sintering or hot isostatic pressing (HIP).
Question 5
The coefficient of thermal expansion of cemented tungsten carbide is found to vary with the amount of cobalt used as a metal binder
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : A
Explanation: True, The coefficient of thermal expansion of cemented tungsten carbide is found to vary with the amount of cobalt used as a metal binder
Question 6
The modern production of hard metal is attributed to ________
A. Kieffer
B. Schroter
C. Schwarzkopf
D. Osram Studiegesellschaft
View Answer
Ans : B
Explanation: The modern production of hard metal is attributed to Schroter. The technique involves the blending of WC powder with up-to 20% by weight of a metal of the iron group, particularly Co as a binder metal, compaction of the powder mixture and sintering at a temperature close to the melting point of the binder metal.
Question 7
______ carbide alloys possess better resistance to diffusion wear under seizure conditions.
A. Medium-grained
B. Ultra-fine grained
C. Coarse-grained
D. Fine-grained
View Answer
Ans : C
Explanation: Coarse-grained carbide alloys possess better resistance to diffusion wear under seizure conditions while fine-grained carbide alloys having the greater abrasion resistance and high hardness are suited for the resistance to the attrition type of wear in the region of partial contact and to shear stresses in the seizure area
Question 8
Cemented carbide grades can be classified into _____ groups, according to their density by using Hg as a buoyancy medium.
A. 5
B. 4
C. 3
D. 2
View Answer
Ans : D
Explanation: Cemented carbide grades can be classified into three groups, according to their density by using Hg as a buoyancy medium; WC-Co grades will sink in Hg while WC-TiC-Co and WC-TiC-Ta (Nb)C-Co grades will float on the surface.
Question 9
Which of the following is not a characteristic of cemented carbide cutting tools?
A. Extremely hard
B. Very brittle
C. High red hardness
D. Low red hardness
View Answer
Ans : D
Explanation: Cemented carbide cutting tools are Extremely hard, possess High red hardness and are very brittle. The cutting speed with the use of carbide-tipped tools is increased six to eight times over that with the customary high-speed steel tools.
Question 10
Recarburization is often necessary for carbide produced by the reaction of metal oxide with carbon.
A. TRUE
B. FALSE
C. Can be true or false
D. Can not say
View Answer
Ans : A
Explanation: In carbide powder production by direct reaction of metal oxide with carbon, accurate control of final carbon content is difficult due to a combination of reduction and carburization reactions in a single operation, thus often necessitating crushing and recarburization.